WebDAQ 316 User's Guide
May 2020. Rev 7

Contents
About this User's Guide
Introducing the WebDAQ 316
Se ng up the WebDAQ
Func onal Details
Speciﬁca ons
EU Declara on of Conformity

Trademark and Copyright Informa on
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Other product and company names men oned herein are trademarks or trade names of their respec ve
companies.
© Measurement Compu ng Corpora on. All rights reserved. No part of this publica on may be reproduced,
stored in a retrieval system, or transmi ed, in any form by any means, electronic, mechanical, by photocopying,recording, or otherwise without the prior wri en permission of Measurement Compu ng Corpora on.
No ce
Measurement Compu ng Corpora on does not authorize any Measurement Compu ng Corpora on productfor use in life support systems and/or devices without prior wri en consent from Measurement Compu ng
Corpora on. Life support devices/systems are devices or systems that, a) are intended for surgical implanta on
into the body, or b) support or sustain life and whose failure to perform can be reasonably expected to result ininjury. Measurement Compu ng Corpora on products are not designed with the components required, and are
not subject to the tes ng required to ensure a level of reliability suitable for the treatment and diagnosis ofpeople.

WebDAQ 316 User's Guide

About this User's Guide
This user's guide describes the Measurement Compu ng WebDAQ 316 data acquisi on device, the WebDAQ
web interface, and lists device speciﬁca ons.

Where to ﬁnd more informa on
Addi onal informa on about the WebDAQ Series of internet enabled data loggers is available on our website atwww.mccdaq.com/WebDAQ. You can also contact Measurement Compu ng Corpora on with speciﬁcques ons.
WebDAQ web interface: Open the Help window for informa on about using WebDAQ so ware.
Knowledgebase: kb.mccdaq.com
WiFi adapters approved for use with WebDAQ Series hardware: www.mccdaq.com/pdfs/manuals/wdwiﬁ.pdf
Tech support form: www.mccdaq.com/support/support_form.aspx
Email: techsupport@mccdaq.com
Phone: 508-946-5100 and follow the instruc ons for reaching Tech Support
For interna onal customers, contact your local distributor. Refer to the Interna onal Distributors sec on on our
website at www.mccdaq.com/Interna onal.

Hazardous voltages
Take the following precau ons if you connect hazardous voltages to the WebDAQ 316 spring terminals. A
hazardous voltage is a voltage greater than 42.4 Vpk or 60 VDC to earth ground.
Ensure that hazardous voltage wiring is performed only by qualiﬁed personnel adhering to local electricalstandards.
Do not mix hazardous voltage circuits and human-accessible circuits on the same device.
Make sure that devices and circuits connected to the WebDAQ 316 are properly insulated from humancontact.
When device terminals are hazardous voltage LIVE (>42.4Vpk/60 VDC), you must install the high voltage screw
terminal backshell (ACC-401) to ensure that the terminals are not accessible and that the devices and circuits
connected to the WebDAQ 316 are properly insulated from human contact.
Hazardous loca ons : The WebDAQ 316 is not cer ﬁed for use in hazardous loca ons.
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WebDAQ 316 User's Guide

Introducing the WebDAQ 316
The WebDAQ 316 is part of the WebDAQ Series of Internet enabled data loggers. WebDAQ 316 is athermocouple acquisi on and logging device that provides the following features:
16 diﬀeren al thermocouple inputs
75 S/s/ch sample rate
250 Vrms channel-to-earth isola on
Overvoltage protec on between any two inputs
50/60 Hz noise rejec on
Cold junc on compensa on (CJC)
Auto zero channel
Four bidirec onal, isolated DIO that are individually conﬁgurable for input (trigger) or output (alarm)
10/100 Ethernet interface
Support for USB WiFi adapters for wireless connec vity
Support for USB mass storage devices and SD cards for data logging or ﬁle transfer
Powered by an external power supply
WebDAQ Series devices are designed with an integrated opera ng system and web interface. You communicate
with the device over a network connec on using the web interface opened in a web browser.
Mobile support – access the WebDAQ from any device with a web browser, such as a phone or tablet
Remote monitoring and control
Run simple to complex logging opera ons
Flexible task schedulingPowered by Raspberry Pi
The WebDAQ is designed with the Raspberry Pi Compute Module, featuring a quad core processor with speeds
up to 1.2 GHz, 1GB RAM and 4 GB Flash memory.

Integrated opera ng system and web service
The WebDAQ is a complete data acquisi on system containing an embedded opera ng system and web server.
The opera ng system resides in internal ﬂash memory, and includes a web service and device driver. All
conﬁgura on, acquisi on, and data management is performed using the web interface.

Ethernet interface
The WebDAQ has a built-in 10/100 BASE-T auto-nego a on, high-speed communica on port. You can accessand conﬁgure your WebDAQ from anywhere with access to the network to which it is connected. A unique
MAC address is assigned to each device at the factory. You conﬁgure the Ethernet connec on se ngs through a
web interface. The default network name uses the format webdaq-xxxxxx, where xxxxxx are the lower six digitsof the factory-assigned MAC address. You can change this name with the web interface.

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WebDAQ 316 User's Guide

Open-source so ware
WebDAQ ﬁrmware uses open-source so ware components. Refer to Licenses for the licensing informa on ofeach component. Open-source code is available upon request from info@mccdaq.com.

UnpackingAs with any electronic device, you should take care while handling to avoid damage from sta celectricity. Before removing the board from its packaging, ground yourself using a wrist strap or by simply
touching the computer chassis or other grounded object to eliminate any stored sta c charge.
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WebDAQ 316 User's Guide

Se ng up the WebDAQ
Connec ng to a local area network
The WebDAQ requires a TCP/IP connec on to a network or the Ethernet port of a computer. A standard
Ethernet cable is shipped with the device. The WebDAQ IP address type is set by default for DHCP/Link-Local.
When connected to a network, the device ﬁrst a empts to receive an IP address from a DHCP server. If thisfails, a link-local address is used. Use of a sta c address requires conﬁgura on via the web interface. The IP
address iden ﬁes the WebDAQ on the network, and is used to access the web interface.

Connec ng to a network with DHCP enabled
Connect one end of the Ethernet cable to the connector on the WebDAQ rear panel, and connect the other end
to a 10Base-T or 100Base-TX compa ble Ethernet port, hub, or switch.
Once the device is detected, DHCP assigns an address. A diﬀerent address may be assigned each me thehardware is connected to the network.
WiFi support
A er successfully conﬁguring a wired connec on, you can use the web interface to conﬁgure theWebDAQ for wireless communica on. Refer to the Conﬁguring the WebDAQ for wirelesscommunica on sec on for more informa on.

Connec ng directly to a PC
Connect one end of the Ethernet cable to the connector on the WebDAQ rear panel, and connect the other end
directly to the Ethernet port on a PC. The WebDAQ a empts to communicate with the host PC using
169.254.100.100 – the link-local address stored on the device. The host PC may accept this address or use adiﬀerent address. The link-local address is valid only for communica ons between the WebDAQ and the host PC
to which it is connected.

Connec ng the external power adapter
Connect the network cable before connec ng to external power
Connec ng to the external supply before installing on a network results in the device a emp ng toauto-nego ate a network address before one is available.
Connect the adapter to the power connector labeled EXT PWR on the device rear panel, and plug the AC
adapter into an electrical outlet.
Press the POWER bu on. The POWER LED on the rear panel turns yellow as the hardware starts up, and green
when it is ready for use.

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Detec ng the device on a network
WebDAQ uses the "zeroconf" zero-conﬁgura on protocol to announce its presence on a local area network.
Zeroconf uses a device name which can be accessed from other computers on the network.
Zero-conﬁgura on networking is helpful to ﬁnd your WebDAQ hardware on the network
The easiest way to add zeroconf support to Windows is to install Bonjour Print Services. Bonjour
so ware is Apple's implementa on of zero-conﬁgura on networking, and is readily available as a freedownload – open a browser window and search for Bonjour Print Services. Zeroconf is built into popularapplica ons such as Apple ITunes® and instant messaging so ware, so your computer may alreadysupport it. Many Linux systems will have the avahi version of zeroconf installed by default, so it's likely
zeroconf is available if you're running Linux.

Accessing the WebDAQ web interface
To access the WebDAQ web interface, open a browser window and enter h p://webdaq-xxxxxx.local, where
xxxxxx is the last 6 digits of the MAC address. The MAC address is on a label at the bo om of the WebDAQ
enclosure.
If your network is conﬁgured for the zeroconf protocol, the WebDAQ web interface opens.
If the web interface does not open or an error is returned, install a device discovery tool such as Bonjour
Print Services. Refer to the note above about zero-conﬁgura on networking.
Browser support
The latest version of Chrome, Firefox, Safari, UC Browser, or Opera recommended. Compa ble with theEdge browser version 79 and up. Not recommended for use with earlier versions of the Edge browser.
Not recommended for use with Internet Explorer.
The WebDAQ web interface is shown here.

Figure 1. WebDAQ web interface
Use the WebDAQ web interface to conﬁgure hardware and acquisi on op ons, schedule and run jobs, and toview and manage data. The Help window provides details about all components on the web interface.
Once a connec on is established and you can communicate to the device, you can change the conﬁgura on forother network scenarios.
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WebDAQ 316 User's Guide

Conﬁguring the WebDAQ for wireless communica on
Once communica on is established on a wired network, you can connect a WiFi adapter to the USB port anduse the web interface to conﬁgure the WebDAQ for communica on over a wireless network. With the WebDAQ
connected through the wired connec on, perform the following procedure.
1. Connect an approved WiFi adapter to the USB port on the WebDAQ rear panel.
A list of WiFi adapters approved for use with WebDAQ Series hardware is available on our website atwww.mccdaq.com/pdfs/manuals/wd-wiﬁ.pdf.
2. Open the WebDAQ web interface in a browser window and go to the Device window, Network tab.
3. Select WiFi. Once the list of available networks updates, select the wireless network that you want toconnect to, and enter the password, if any.
If the connec on is successful, the selected wireless network will show above this list with a checkmark
next to it.
You can click on the selected network to open a WiFi Network Se ngs dialog box where you can forget thecurrent network or conﬁgure the IP address type (DHCP/Link-Local or Sta c).
4. Disconnect the Ethernet cable from the LAN connec on.
Wait a few seconds, and refresh the browser window.
Changing to a wireless network may require a reboot
If a connec on can't be established a er changing the network, you may need to reboot the opera ng
system and restart the WebDAQ using the Power bu on.

Conﬁguring the network router for communica on across networks
To communicate with the WebDAQ over the internet from a computer connected to a diﬀerent network, youmust change the network conﬁgura on of the network router.
Cau on! This procedure should only be performed by a network administrator or computer
professional. Incorrect se ngs can signiﬁcantly disrupt a network.
In the following procedure, the WebDAQ is installed on the host LAN, the computer is installed on the client
LAN, and it is assumed that you have successfully connected the device to a local network.
1. Determine the IP address of the WebDAQ – open the Device window from the web interface, and note the
IP Address value on the Network Se ngs tab.
2. Conﬁgure your router so that the address determined above is a sta c address. The procedure foraccomplishing this varies between routers; refer to your router documenta on for instruc ons.
3. Conﬁgure the ﬁrewall/router to forward an unused port to port 80 on the WebDAQ at the IP address
conﬁgured for the device.
Note the sta c IP address assigned to the router – this is referred to as the WAN address.
4. To access your WebDAQ from a remote loca on, enter the WAN address followed by the port selected
above preceded by a colon in the web browser.
The format of the address entered in the browser is: 00.000.00.00:00000 (WAN address of router:port
selected for the WebDAQ).

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WebDAQ 316 User's Guide

Security
Use the web interface to set the level of access to the website and to change the administrator password.
High: access to the web page requires a password.
Medium: access to the web page is permi ed for any user, and data can be read by any user, but changes
to the device conﬁgura on or ﬁles require a password.
Oﬀ: full access is permi ed for all users; no password is required.
By default, security access is set to "Oﬀ", and the administrator password is set to "admin".
To change the security level or password, open the web interface and go to the Device window, Security tab.
Use the device Reset bu on to restore security se ngs to factory default values.

Restoring factory default se ngs
To restore network conﬁgura on and security se ngs to the factory default values, use a paper clip to press
the CONFIG RESET bu on. When pressed, the default network and security se ngs are wri en to the device
and the WebDAQ is rebooted.
Factory default se ngs
Parameter
IP address
Subnet mask
Gateway
DHCP se ng
Security level
Password for the admin
account
Password for the shareaccount
Device nameSpeciﬁca on
192.168.0.101
255.255.255.0
192.168.0.1
DHCP + link-local enabledOﬀadmin (case-sensi ve)
share (case-sensi ve)
webdaq-xxxxxx, where xxxxxx is the last 6 digits of the MAC address(printed on the label on the underside of the device).

The network se ngs, security level, user account passwords and device name can be changed with the
WebDAQ web interface.
Shared folders and mapped drives are reset when factory defaults are restored.
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Func onal Details
Func onal block diagram
Device func ons are illustrated in the block diagram shown here.

Figure 2. Func onal block diagram

Front panel components

Figure 3. Front panel
1

Screw terminal

2

Spring terminal

page 9WebDAQ 316 User's Guide

Screw terminal (Digital connec ons)
Connect up to four digital I/O lines (DIO0 to DI03) to the detachable screw terminal.

Figure 4. Screw terminal pinout
The digital ground (GND) terminals provide a common ground for the digital bits.
The digital I/O lines are electrically isolated from the analog circuits. Each bit is individually conﬁgurable for
input or output, and features Schmi trigger inputs and open drain outputs. All DIO channels are pulled high to
5 V.
Any digital bit can be conﬁgured with the web interface as a trigger to start or stop an acquisi on, to trigger an
alarm and be driven high or low when an alarm or occurs, or be driven high or low when an event condi on
occurs.

Spring terminal (Analog connec ons)
Connect up to 16 thermocouple or voltage inputs (TC0+/TC0– to TC15+/TC15–) and two common reference
connec ons (COM) to the 36-posi on detachable spring terminal.
Cau on! We strongly recommend that you ground yourself using a wrist strap before handlingthermocouple sensors.

Figure 5. Spring terminal pinout

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Thermocouple connec ons
A thermocouple consists of two dissimilar metals that are joined together at one end. When the junc on of themetals is heated or cooled, a voltage is produced that correlates to temperature.
The WebDAQ 316 supports type J, K, S, R, B, E, T, N thermocouples (TC), and provides overvoltage protec on
between any two inputs. A typical thermocouple connec on is shown in the following ﬁgure.

Figure 6. Typical thermocouple connec on
Connect the shield to a common mode voltage reference on the thermocouple. A valid reference is voltage
within ±1.2 V of all the connected thermocouples.

Minimizing thermal gradients
Changes in the ambient air temperature near the thermocouple connectors or a thermocouple wire conduc ng
heat directly to terminal junc ons can cause thermal gradients. Observe the following guidelines to minimize
thermal gradients and improve system accuracy:
Use small-gauge thermocouple wire. Smaller wire transfers less heat to or from the terminal junc on.
Run thermocouple wiring together near the spring terminal connector to maintain a consistenttemperature.
Avoid running thermocouple wires near hot or cold objects.
Minimize adjacent heat sources and air ﬂow across the terminals.
Keep the ambient temperature as stable as possible.
Increasing the thermocouple length
If you need to increase the length of your thermocouple, use the same type of TC wires to minimize theerror introduced by thermal EMFs.

Analog input circuitry
Each channel passes through a diﬀeren al ﬁlter and then is mul plexed and sampled by a 24-bit ADC. The
channels share a common ground (COM) that is isolated from the digital subsystem.
The circuitry for one thermocouple channel is shown in here.

Figure 7. Input circuitry of one TC channel
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Open thermocouple detec on
Each channel has an open thermocouple detec on (OTD) circuit which consists of a current source between the
TC+ and TC– terminals. If an open thermocouple is connected to the channel, the current source forces a fullscale nega ve voltage across the terminals.

Input ImpedanceEach channel has a resistor that produces an input impedance between the TC and COM terminals. The gain
and oﬀset errors resul ng from the source impedance of connected thermocouples are negligible for mostapplica ons. Thermocouples with a longer lead length can introduce more signiﬁcant errors.
Overvoltage protec on
WebDAQ provides 30 V overvoltage protec on between any two inputs.

Thermocouple measurement accuracy
Thermocouple measurement errors depend partly on the type and accuracy of the thermocouple, thetemperature being measured, the resistance of the thermocouple wires, and the cold-junc on temperature.
For increased accuracy, follow the guidelines in the Minimizing thermal gradients sec on, and use the auto zerochannel to compensate for oﬀset errors.

Cold-junc on accuracy
Heat dissipated by nearby heat sources can cause errors in thermocouple measurements by hea ng theWebDAQ 316 terminals to a diﬀerent temperature than the cold-junc on compensa on sensor. Thermal
gradient across the terminals can cause the terminals of diﬀerent thermocouple channels to be at diﬀerent
temperatures, which creates accuracy errors and aﬀects the rela ve accuracy between channels.
The temperature measurement accuracy speciﬁca ons include errors caused by the thermal gradient acrossthe WebDAQ 316 terminals for conﬁgura ons with the terminals facing forward or upward.

Auto zero channel
The WebDAQ 316 has an internal auto zero channel to compensate for oﬀset errors. When enabled, theWebDAQ measures the autozero channel and subtracts that measurement from the measurement of eachthermocouple channel. Use the web interface to enable auto zero. WebDAQ 316 speciﬁca ons assume that
auto zero is enabled and applied to every sample.

Rear panel components

Figure 8. Rear panel
123External power
connector
Power bu on
Func on bu on

4

LED indicators (4)7Ethernet connector

56

SD card slot
Factory reset bu on(recessed)

8
9Ground connector
USB connectors (2)page 12WebDAQ 316 User's Guide

External power connector
Connect the external AC adapter to the connector labeled EXT PWR on the rear panel. Click here to jump to thepower speciﬁca ons.

Power bu on
The bu on labeled POWER turns the WebDAQ device on and oﬀ. WebDAQ hardware is designed with a 2-pin
jumper (W1) that users can remove to con nuously power the device. The behavior of the POWER bu on
when jumper W1 is installed or removed is listed in the following table.
Jumper W1 installed(factory default se ng)

Jumper W1 removed

When the device is oﬀ, press the POWER bu on
brieﬂy to turn the device on.

The device is always on as long as the power
adapter is connected and receiving power(Power-On Mode).

When the device is on, press the POWER bu on
for approximately 1 second to shut down theopera ng system and WebDAQ hardware;release the bu on when the POWER LED blinks
yellow.
The opera ng system automa cally powers oﬀ
the device at the end of the shutdown
procedure.
Press and hold the POWER bu on for
approximately 4 seconds to force the device topower oﬀ. Any unsaved changes may be lostwhen powering down using this method.

Press for approximately 1 second to reboot thedevice; release the bu on when the POWER LED
blinks yellow.

Refer to Power-On Mode for the procedure to remove jumper W1 and enable Power-On mode.
The WebDAQ device can also be restarted or shut down using the web interface; refer to the WebDAQ
help for details.

Func on bu on
The bu on labeled FUNC has two func ons; it can be used to eject external media or to start/stop an
acquisi on.
Eject external media (default): Pressing the bu on unmounts all removable media so they can be safely
removed from the device.
Start or stop an acquisi on (requires conﬁgura on with the web interface): When conﬁgured, pressing
this bu on starts an acquisi on, or stops an acquisi on that is currently running.
Use the web interface to safely unmount removable media, when present.
When removable media is plugged into the WebDAQ, the opera ng system opens it for wri ng. To safely
remove the media, you must unmount it ﬁrst.
When a job is conﬁgured to log data to external media, pressing FUNC while the job is running will not eject themedia.
The MEDIA LED is steady green when all media is unmounted and safe to remove, and oﬀ when all media isremoved.

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LED status indicators
The WebDAQ has four LEDs on the rear panel that indicate the status of power and host communica ons. The
following table deﬁnes the LED states during normal opera on.
LED states – normal opera ng mode
Label
1: POWER

2: STATUS

State
Steady yellow
Steady green
Blinking yellow
Oﬀ
Blinking yellow
Steady green
Flashing green
100 ms on/2s oﬀ)
Blinking heartbeat

3: ERROR

Blinking green
Oﬀ
Blinking yellow

4: MEDIAOﬀ
Blinking yellow
Steady yellow
Blinking green
Steady green

Descrip on
Device is boo ng up
Device boot is successful.
Device is shu ng down.
Device is oﬀ.
Device is conﬁguring hardware.
Hardware conﬁgura on is complete.
Wai ng for a scheduled start condi on to be met.
Scheduled start condi on is met; wai ng for job start
condi on to be met.
Data is being acquired (job start condi on is met).
No error detected.
Error condi on is detected. This LED blinks even when theso ware is conﬁgured to ignore the error.
Error state is cleared when the next schedule starts.
No error detected.
A job is conﬁgured to log to external media, but the job
hasn't started yet; pushbu on will not let you eject media.
External media is inserted into the SD card slot or USB
storage port.
Currently logging to an external SD card or USB storage
device.
Media has been made safe for removal using the func on
bu on, but has not been removed.

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WebDAQ LEDs behave diﬀerently when so ware is updated on the device. The following table deﬁnes the LED
states during a so ware update.
LED states – so ware update mode
LED
All LEDs
POWER
STATUS

State
Solid yellow
Blinking yellow
Blinking green
Blinking yellow

ERROR

Blinking green
Blinking yellow

Descrip on
So ware update is star ng
So ware update is running
Update ﬁle is located; device is being updated
Update ﬁle cannot be located; insert media with update
ﬁleUpdate is successful; device will reboot in approximately
5 seconds
Update failed; user must retry

Refer to Upda ng WebDAQ ﬁrmware for more informa on about WebDAQ ﬁrmware.

SD card slot
The SD slot accepts SD (Secure Digital), SDHC, SDXC, MMC, and TransFlash memory cards. Memory cards can beejected using the web interface or the hardware FUNC bu on, unless the bu on is conﬁgured to start/stop an
acquisi on.
When removable media is plugged into the WebDAQ, the opera ng system opens it for wri ng. Use the FUNC
bu on or web interface to unmount the SD card before removing.

Factory reset bu on
The recessed bu on labeled CONFIG RESET restores factory default se ngs. When pressed, the default se ngs
are wri en to the device and the WebDAQ is rebooted. Refer to the Restore factory default se ngs sec on fora list of the default se ngs that are restored.

Ethernet connector
The WebDAQ has one 10 Base-T/100 Base-TX, auto-nego a on, high-speed communica on port. The port
connector is an RJ-45, eight-posi on connector. The Ethernet port accepts shielded or unshielded twisted paircable. The maximum communica on distance without using a repeater is 100 m (328 ). For CE compliance themaximum distance is 3 m (9.84 ).

Ground connector
The WebDAQ ships with a ground screw in the connector labeled #6-32. To ground the WebDAQ chassis, a ach
a ring lug to a 14 AWG (1.6 mm) wire. Connect the ring lug to the grounding screw on the WebDAQ rear panel.
A ach the other end to a safety ground.

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USB connectors
The two high-speed USB ports can be used for connec ons to a mass storage device and approved WiFi
adapter.
When removable media is plugged into the WebDAQ, the opera ng system opens it for wri ng. Use the FUNC
bu on or web interface to unmount the USB device before removing.
Use a self-powered hub when external media requires higher current
USB-powered hard drives may use an excessive amount of current during opera on. The WebDAQ
device could shut down or experience other errors if the power requirements of a connected device
exceed the power available. Use a self-powered hub if the current requirement of external media
exceeds 500 mA.
We recommend that you connect USB-powered hard drives before powering up the WebDAQ.

Logging data
You can log up to 3 GB of data to internal WebDAQ storage. To generate larger data ﬁles, log data to external
media with a storage capacity suitable for the acquisi on. USB drives and SD cards are available in diﬀerent ﬁleformats, and OS support for each format varies. WebDAQ supports FAT32, exFAT, ext2/3/4, NTFS ﬁle systems.
When genera ng large data ﬁles with Windows or Mac, or transferring ﬁles between opera ng systems, werecommend using external media forma ed with the exFAT ﬁle system, such as an SDXC memory card. Whenrunning Linux, use external media forma ed with the ex2/ex3/ex4 ﬁle system. Refer to the WebDAQ help FAQ
for more informa on about ﬁle formats.
File too large error
If you generate data that exceeds the capacity of the selected storage loca on, a "File too large" error isreturned and the acquisi on stops. To avoid interrup ons, select a storage loca on with a large capacity.

Logging data to external media
Acquiring data at high speeds can generate large ﬁle sizes. If you expect to acquire a large amount ofdata to a single ﬁle when logging to external media, do not use media forma ed with the FAT32 ﬁlesystem. FAT32 is limited to a 4 GB maximum ﬁle size. If the log ﬁle on FAT32 media grows beyond thatsize, a "File too large" error is returned and the acquisi on stops. Before star ng a logging session ofthis type, reformat the media using a diﬀerent ﬁle system such as NTFS. Refer to the Frequently Asked
Ques ons help topic for more informa on about ﬁle systems.

Power-On Mode
WebDAQ Series hardware can be conﬁgured to start automa cally when power is applied, instead of requiring
users to press the POWER bu on. This is useful if the WebDAQ is opera ng in a remote loca on and a power
loss occurs. This "power-on mode" is enabled by removing a 2-pin jumper (labeled W1) from the WebDAQ
circuit board.
When jumper W1 is removed, the device does not shutdown completely unless the power adapter is
unplugged from the device or power source.
Perform the procedure below to remove jumper W1 from the WebDAQ circuit board and enable power-on
mode.
Cau on! The discharge of sta c electricity can damage some electronic components. Before removing
the WebDAQ device from its housing, ground yourself using a wrist strap or touch the computer chassis
or other grounded object to eliminate any stored sta c charge.
1. Power down the WebDAQ device and disconnect the power supply.
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WebDAQ 316 User's Guide

2. On the rear panel, remove the Ethernet cable, power cable, SD card, and any USB devices.
3. Remove the #6-32 ground screw.
4. Remove the nut and washer from the EXT PWR connector.
5. Remove the two front panel bezel screws and remove the front bezel.
6. Slide out the circuit board with the front panel intact.
7. Remove jumper W1 from the speciﬁed loca on shown below.

8. Slide the circuit board back into the enclosure.
9. A ach the front bezel and secure with the two bezel screws removed in step 5.
10. Secure the power connector with the nut and washer (removed in step 4) to the power connector, anda ach the ground screw, Ethernet and power cables, and any USB devices.
To automa cally run a schedule when the WebDAQ powers up, enable the "Automa cally start schedule on
system startup" op on on the Schedule Se ngs dialog box of the web interface. If a power cycle occurs, theschedule will restart from the beginning, regardless of which job was running when the power was lost. In
order to retain the data from each schedule start, make sure to set the logging op on for each job to "Append
Date/Time to File Name" so that each run a er power loss creates a new data ﬁle rather than overwri ng theoriginal ﬁle. Refer to the WebDAQ help for details about how to conﬁgure schedule and logging op ons.
Enabling power-on mode with a complex or date/ me triggered schedule
When running a complex or date/ me-triggered schedule with both power-on mode and auto startschedule enabled, be aware that the schedule may not run automa cally a er a power cycle if the dateor me trigger is no longer valid. In this case, the user may s ll access the WebDAQ remotely to modify
the start se ngs.

Replacing the ba ery
A bu on cell lithium ba ery provides the me reference for WebDAQ hardware when the device is powered
oﬀ. The average lifespan of the ba ery is approximately 10 years.
Cau on! The discharge of sta c electricity can damage some electronic components. Before removing
the WebDAQ from its housing, ground yourself using a wrist strap or touch the computer chassis orother grounded object to eliminate any stored sta c charge.
1. Power down the WebDAQ device and disconnect the power supply.
2. On the rear panel, remove the Ethernet cable, power cable, SD card, and any USB devices.
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WebDAQ 316 User's Guide

3. Remove the #6-32 ground screw.
4. Remove the nut and washer from the EXT PWR connector.
5. Remove the two front panel bezel screws and remove the front bezel.
6. Slide out the circuit board with the front panel intact.
7. Remove the ba ery by sliding it forward toward the slot, and replace with a 3 V lithium coin cell ba ery.
8. Slide the circuit board back into the enclosure.
9. A ach the front bezel and secure with the two bezel screws removed in step 5.
10. Secure the power connector with the nut and washer removed in step 4, to the power connector, a ach theground screw, Ethernet and power cables, and any USB devices.
Set the device system clock from the Device window, Device Info tab on the web interface.

Upda ng WebDAQ ﬁrmware
Device ﬁrmware is bundled with the opera ng system, web server, and documenta on in a so ware update(*.swu) ﬁle. Firmware updates are posted on the Measurement Compu ng Firmware Updates page and areavailable for download.
Use the web interface to install the *.swu update ﬁle. Open a browser window and enter h p://webdaqxxxxxx.local/Help, where xxxxxx is the last 6 digits of the MAC address – see the label on the bo om of theenclosure. Refer to the "Upda ng WebDAQ Firmware" help topic or FAQ for instruc ons.

Calibra ng the hardware
The Measurement Compu ng Manufacturing Test department performs the ini al factory calibra on. Returnthe device to Measurement Compu ng Corpora on when calibra on is required. The recommended calibra oninterval is one year.
Contents

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WebDAQ 316 User's Guide

Speciﬁca ons
All speciﬁca ons are subject to change without no ce.
Typical for 0 °C to 50 °C unless otherwise speciﬁed.

Thermocouple input
Table 1. Thermocouple input speciﬁca ons
Parameter
Number ofchannels
ADC resolu on
Type of ADC
Sampling mode
Voltagemeasurement
range
Temperature
measurement
rangesTiming mode

Timing mode

Condi onWorks over temperature ranges deﬁned by NIST
(J, K, T, E, N, B, R, S thermocouple types)
Automa cally set
for either highresolu on or highspeed mode basedon the requested
scan rate,
regardless of thenumber ofchannels.
High-resolu on
High-speed

Common-mode
voltage range
Common-mode
rejec on ra o
(CMRR)

Input bandwidth

High-resolu on
noise rejec on
Overvoltage
protec on

Speciﬁca on
16 thermocouple channels
1 internal auto zero channel
1 internal cold-junc on compensa on channel
24 bits
Delta-Sigma
Scanned±78.125 mV

High-resolu onmode at DC
and 50 to 60 Hz
High-speed mode
at 0 to 60 Hz
High-resolu on
mode
High-speed mode
50 Hz and 60 Hz

High resolu on: requested scan rate is ≤1 Hz
High-speed: requested scan rate is >1 Hz

Conversion Time (per channel): 55 ms
Sample Rate (all channels): 1 S/s
Conversion Time (per channel): 740 µs
Sample Rate: 75 S/s/ch
Channel-to-COM: ±1.2 V min
COM-to-earth ground: ±250 V
Channel-to-COM: 100 dB
COM-to-earth ground: >170 dB
Channel-to-COM: 70 dB
COM-to-earth ground: >150 dB
14.4 Hz
78 Hz
60 dB±30 V between any two inputs
page 19

WebDAQ 316 User's GuideDiﬀeren al input
impedance
Input current
Input noise

Gain error

78 MΩ

High-resolu on
mode
High-speed mode
High-resolu on
mode
High-speed modeOﬀset error

Oﬀset error fromsource impedanceCold-junc oncompensa on
accuracyWarm-up me

High-resolu on
mode
High-speed mode
0 °C to 60 °C

50 nA
200 nVrms
7 µVrms
0.03% typ at 25 °C
0.07% typ at 0 °C to 60 °C
0.15% max at 0 °C to 60 °C
0.04% typ at 25 °C
0.08% typ at 0 °C to 60 °C
0.16% max at 0 °C to 60 °C
4 µV typ, 6 µV max
14 µV typ, 17 µV max
Add 0.05 µV per Ω, when source impedance >50 Ω
0.8 °C typ, 1.7 °C max

The device is lying
ﬂat or facing
upward, with aconstant ambient
temperature.

15 minutes recommended

Temperature measurement accuracy
Measurement sensi vity represents the smallest change in temperature that a sensor can detect. It is afunc on of noise. The values assume the full measurement range of the standard thermocouple sensor per
ASTM E230–87.
Table 2. Temperature accuracy speciﬁca ons
Parameter
Measurement
sensi vity

Condi onHigh-resolu on
mode
High-speed mode

Speciﬁca on
Type J, K, T, E, N: <0.02 °C
Type B, R, S: <0.15 °C
Type J, K, T, E: <0.25 °C
Type N: <0.35 °C
Type B: <1.2 °CType R, S: <2.8 °C

The following ﬁgures show the errors for each thermocouple type when connected to the WebDAQ 316 with
auto zeroing performed. The ﬁgures display the maximum error over a full temperature range, and the typicalerror at room temperature. The ﬁgures account for gain errors, oﬀset errors, diﬀeren al and integral
nonlinearity, quan za on errors, noise errors, 50 Ω lead wire resistance, and cold-junc on compensa onerrors. The ﬁgures do not account for the accuracy of the thermocouple itself.

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WebDAQ 316 User's Guide

Thermocouple Types J and N Errors

Thermocouple Type K Errors

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WebDAQ 316 User's Guide

Thermocouple Type T and E Errors

Thermocouple Type B Errors

Thermocouple Type R and S Errors
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WebDAQ 316 User's Guide

Digital input/output
Table 3. Digital input/output speciﬁca ons
Parameter
Digital type
Number of I/O
Conﬁgura on
Power oncondi ons
Pull-up
conﬁgura on
Input frequency
range
Input high voltage
thresholdInput low voltage
thresholdSchmi trigger
hysteresis
Input high voltage
limit
Input low voltage
limit
Output voltage
range
Output oﬀ state
leakage current
Output sinkcurrent capability
Output transistor
on-resistance(drain to source)

Speciﬁca on
CMOS (Schmi trigger) input / open drain output
One port of 4 bits
Each bit can be independently conﬁgured for input or output
Power on reset is input mode
Each bit is pulled up to 5 V with a 100 kΩ resistor
DC – 10 kHz (Note 1)
1.9 V min, 3.6 V max
2.3 V max, 1.0 V min
0.6 V min, 1.7 V max
15 V max–0.5 V absolute min
0 V recommended min
0 V to +5 V (no external pull up resistor)
0 V to +15 V max (Note 2)
10 µA max
100 mA max (con nuous) per output pin
1.6 Ω

Note 1. Applying a signal with a frequency higher than this speciﬁca on will adversely aﬀect system
performance and could cause errors.
Note 2. The external pull-up resistor is connected between the digital output bit and an external supply. Adding
an external pull-up resistor connects it in parallel with the internal 100 kΩ pull-up resistor of that par cular
digital input/output bit to the internal 5 V supply. Careful considera on should be made when considering theexternal pull-up resistor value and the resultant pull-up voltage produced at the load.

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WebDAQ 316 User's Guide

Network
Ethernet connec on
Table 4. Ethernet connec on speciﬁca ons
Parameter
Ethernet typeCommunica on
rates
Connector
Cable length
Addi onal
parameters

Speciﬁca on
100 Base-TX
10 Base-T
10/100 Mbps, auto-nego ated
RJ-45, 8 posi on
100 meters (328 feet) max
For CE compliance the max length is 3 meters (9.84 feet)
HP Auto-MDIX support

Network conﬁgura on
Table 5. Network conﬁgura on
Parameter
Network IP
conﬁgura on

Network device
nameNetwork namepublica on
User accounts

Speciﬁca on
DHCP, link-local, sta c
DHCP may be disabled by the user and a sta c IP address assigned
If DHCP is enabled but is unsuccessful at obtaining an IP address the device will fallback to link-local and request the IP address 169.254.100.100.
The name used for detec ng the device using mDNS (zero-conf). This name may bechanged using the web interface.
By mDNS
There are two built-in user accounts:
admin
share
These accounts are case-sensi ve and cannot be changed using the web interface.

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WebDAQ 316 User's Guide

Factory default se ngs
Table 6. Factory default se ngs
Parameter
Factory default IP
address
Factory default
subnet mask
Factory default
gateway
Factory default
DHCP se ng
Factory default
password foradmin accountFactory default
password for shareaccount
Factory default
device nameSpeciﬁca on
192.168.0.101
255.255.255.0
192.168.0.1
DHCP + link-local enabledadmin
Passwords are case sensi ve and can be changed using the web interface.
share
Passwords are case sensi ve and can be changed using the web interface.
webdaq-xxxxxx, where xxxxxx is the last 6 digits of the MAC address (printed on thelabel on the underside of the device).

Note 3. Shared folders and mapped drives are reset when factory defaults are restored.

Processor / Memory
Table 7. Processor / memory speciﬁca ons
Parameter
Microprocessor
MemorySpeciﬁca on
Type: Quad core Broadcom BCM2837
Speed: 1.2 GHz
RAM: 1 GB LPDDR2Flash: 4 GB eMMC (3 GB available for user data storage)

USB ports
Table 8. USB speciﬁca ons
Parameter
Number of USB
ports
USB device type
Devicecompa bility

Speciﬁca on
Two
USB 2.0 (high-speed)
USB 1.1, USB 2.0, USB 3.0

Note 4. The USB ports are provided for connec on to a mass storage device or approved WiFi adapter.

SD memory card slot
Table 9. SD card speciﬁca ons
Parameter
Memory card type
File systems
supported

Speciﬁca on
SD, SDHC, SDXC, MMC, TransFlash
FAT16, FAT32, exFAT, ext2/3/4, NTFS

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WebDAQ 316 User's Guide

LED indicators
Table 10. LED speciﬁca ons – normal opera ng mode
Label
1: POWER

2: STATUS

State
Steady yellow
Steady green
Blinking yellow
Oﬀ
Blinking yellow
Steady green
Flashing green
100 ms on, 2s oﬀ
Blinking heartbeat
Blinking green

3: ERROR

Oﬀ
Blinking yellow

4: MEDIAOﬀ
Blinking yellow
Steady yellow
Blinking green
Steady green
Oﬀ

Descrip on
Device is boo ng up.
Device boot is successful.
Device is shu ng down.
Device is oﬀ.
Device is conﬁguring hardware.
Hardware conﬁgura on is complete.
Wai ng for the schedule start condi on to be met. (Note 5)
The conﬁgured schedule start condi on is met; wai ng for job
start condi on to be met. (Note 5)
The conﬁgured job start condi on is met – the job is running.
(Note 5)
Device is oﬀ.
Error condi on is detected. LED blinks even when the so ware
is conﬁgured to ignore the error.
Error state is cleared on the next schedule start.
No error is detected, or the device is oﬀ
A job is conﬁgured to log to external media, but the job hasn't
started yet; push bu on will not let you eject media.
External media is inserted into the SD card slot or USB storage
port.
Currently logging to an external SD card or USB storage device.
Media has been made safe for removal using the FUNC bu on,
but is s ll inserted in the device.
No external media is detected, or the device is oﬀ.

Note 5. Use the WebDAQ so ware to conﬁgure start and stop se ngs for jobs and schedules.
Table 11. LED speciﬁca ons – so ware update mode
LED
All LEDs
1. POWER
2. STATUS

State
Solid yellow
Blinking yellow
Blinking green
Blinking yellow

3. ERROR

Blinking green
Blinking yellow

Descrip on
So ware update is star ng.
So ware update is running.
Update ﬁle is located; device is being updated.
Update ﬁle cannot be located; insert media containing the
update ﬁle.
Update is successful; device reboot in approximately 5 seconds.
Update failed; user must retry.

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WebDAQ 316 User's Guide

Push bu ons
Table 12. Push bu on speciﬁca ons
Component
Power bu on

Label
POWER

Descrip on
W1 jumper installed (factory default) (Note 6)
When device is oﬀ; press brieﬂy to turn the device on
When device is on:
Press for ~1 second to shuts down the device; release
the bu on when the POWER LED blinks yellow
Press and hold ~4 seconds to force the device to poweroﬀ
W1 jumper removed (Note 6):
Device will always be on if power is applied
Press for ~1 second to reboot the device; release the bu on
when the POWER LED blinks yellow

Func on bu on

FUNC

Dual func on:
Ejects, or safely unmounts, all removable media for safe
removal from the device (default)This func on is disabled when a job that uses external
media is running
The MEDIA LED is steady green when all media isunmounted but s ll inserted in the device
Starts or stops an acquisi on; requires conﬁgura on via the
web interface

Factory reset
bu on

CONFIGRESET

Restores network se ngs to factory default values; refer to the
Factory default se ngs table for values.

Note 6. Refer to this circuit board image for the loca on of the W1 jumper.

Ground connector
Table 13. Ground connector speciﬁca ons
Component
Ground connector

Label
#6-32

Descrip on
Connector port for the #6-32 ground screw

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WebDAQ 316 User's Guide

Power
Table 14. Power speciﬁca ons
Parameter
Input voltage
Input wa age
External power
adapter
Power behavior

Condi ons
Center posi ve
p/n PS9V1AEPS230V(Note 7)
W1 jumper
installed (factory
default)
W1 jumper
removedBa eryBa eryreplacement

Speciﬁca on
6 VDC to 16 VDC
4 W typ, 10 W max
Phihong PSC15R-090 15 W adapter included. 9 volts, 1.67 amps,
110 VAC to 240 VAC input range required.
So power on using the momentary power bu on; device canturn its power oﬀ to shut down. Device does not resume
opera on if power is lost.
Device is always on if power is applied. Power bu on func ons
only as a reboot bu on.
One 3 V bu on cell lithium ba ery required to maintain me of
day clock when device is powered oﬀ.
Panasonic BR-1225 3V lithium coin cell ba ery or equivalent;user-replaceable.
Refer to the Replacing the Ba ery sec on for the replacement
procedure.

Note 7. If using a diﬀerent supply, ensure that it has a posi ve center pin.

Mechanical
Table 15. Mechanical speciﬁca ons
Parameter
Dimensions(L × W × H)
WeightSpeciﬁca on
158.8 × 146.1 × 38.1 mm (6.25 × 5.75 × 1.50 in.)
177.0 × 146.1 × 38.1 mm (6.97 × 5.75 × 1.50 in.) includes spring terminal
635 g (1.45 lb)

Environmental
Table 16. Environmental speciﬁca ons
Parameter
Opera ng
temperature range
Storagetemperature range
Ingress protec on
Opera ng humidity
Storage humidity
Maximum al tude
Pollu on DegreeSpeciﬁca on
0 °C to 50 °C max–40 °C to 85 °C
IP30
10% to 90% RH, noncondensing
5% to 95% RH, noncondensing
2,000 m (6,562 )2

Note 8. WebDAQ opera on is intended for indoor use only, but may be used outdoors if installed in a suitableenclosure.

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WebDAQ 316 User's Guide

Safety voltages
Connect only voltages that are within the limits speciﬁed in this table.
Table 17. Safety speciﬁca ons
Parameter
Between any two
terminals
Channel-tochannel isola on
Channel-to-earth
ground isola on

Condi ons

Speciﬁca on±30 V maxNone

Con nuous
Withstand

60 VDC for analog inputs, 15 VDC for DIO, CAT I
60 VDC, veriﬁed by a 5 second dielectric withstand test

Measurement Category I is for measurements performed on circuits not directly connected to the electrical
distribu on system referred to as MAINS voltage. MAINS is a hazardous live electrical supply system thatpowers equipment. This category is for measurements of voltages from specially protected secondary circuits.
Such voltage measurements include signal levels, special equipment, limited-energy parts of equipment,
circuits powered by regulated low-voltage sources, and electronics.
Measurement Categories CAT I and CAT O are equivalent. These test and measurement circuits are for othercircuits not intended for direct connec on to the MAINS building installa ons of Measurement Categories CAT
II, CAT III, or CAT IV.
Cau on! Do not connect the WebDAQ 316 to signals or use for measurements within Measurement
Categories II, III or IV.

Signal connectors
Table 18. Screw terminal speciﬁca ons
Parameter
Connector types
Screw terminal
wiringSpring terminal
wiringSpeciﬁca on
36-posi on spring terminal for thermocouple connec ons
6-posi on screw terminal for digital connec ons
14 to 30 AWG copper conductor wire with 5 to 6 mm (0.20 to 0.24 in.) of insula on
stripped from the end
16 to 28 AWG copper conductor wire with 7 mm (0.28 in.) of insula on stripped fromthe end

Screw terminal
Table 19. Screw terminal pinout
Terminal
#
1
2
3

Label
GND
DIO0
DIO1

Terminal
Use
Digital ground
Digital bit 0
Digital bit 1

#
4
5
6

page 29

Label
DIO2
DIO3
GND

Use
Digital bit 2
Digital bit 3
Digital groundWebDAQ 316 User's Guide

Spring terminal
Table 20. Spring terminal pinout
Terminal
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

Label
NC
TC0[+]
TC1[+]
TC2[+]
TC3[+]
TC4[+]
TC5[+]
TC6[+]
TC7[+]
TC8[+]
TC9[+]
TC10[+]
TC11[+]
TC12[+]
TC13[+]
TC14[+]
TC15[+]COM

Terminal
Use
No connec on
Channel 0 HI
Channel 1 HI
Channel 2 HI
Channel 3 HI
Channel 4 HI
Channel 5 HI
Channel 6 HI
Channel 7 HI
Channel 8 HI
Channel 9 HI
Channel 10 HI
Channel 11 HI
Channel 12 HI
Channel 13 HI
Channel 14 HI
Channel 15 HI
Common

#
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46

Contents

page 30

LabelNC
TC0[–]
TC1[–]
TC2[–]
TC3[–]
TC4[–]
TC5[–]
TC6[–]
TC7[–]
TC8[–]
TC9[–]
TC10[–]
TC11[–]
TC12[–]
TC13[–]
TC14[–]
TC15[–]
COM

Use
No connec on
Channel 0 LO
Channel 1 LO
Channel 2 LO
Channel 3 LO
Channel 4 LO
Channel 5 LO
Channel 6 LO
Channel 7 LO
Channel 8 LO
Channel 9 LO
Channel 10 LO
Channel 11 LO
Channel 12 LO
Channel 13 LO
Channel 14 LO
Channel 15 LO
CommonWebDAQ 316 User's Guide

EU Declara on of Conformity
EU Declara on of Conformity
According to ISO/IEC 17050-1:2010
Manufacturer: Measurement Compu ng Corpora on
Address: 10 Commerce Way
Norton, MA 02766
USA
Product Category: Electrical equipment for measurement, control and laboratory use.
Date and Place of Issue: May 31, 2017, Norton, Massachuse s USA
Test Report Number: EMI7018.17
Measurement Compu ng Corpora on declares under sole responsibility that the product
WebDAQ 316
is in conformity with the relevant Union Harmoniza on Legisla on and complies with the essen al
requirements of the following applicable European Direc ves:
Electromagne c Compa bility (EMC) Direc ve 2014/30/EU
RoHS Direc ve (EU) 2015/863 amending Annex II to Direc ve 2011/65/EU
Conformity is assessed in accordance to the following standards:
EMC:
Emissions:
EN 61326-1:2013 (IEC 61326-1:2012), Class A
EN 55011: 2009 + A1:2010 (IEC CISPR 11:2009 + A1:2010), Group 1, Class A
Immunity:
EN 61326-1:2013 (IEC 61326-1:2012), Controlled EM Environments
EN 61000-4-2:2008 (IEC 61000-4-2:2008)
EN 61000-4-3 :2010 (IEC61000-4-3:2010)
EN 61000-4-4 :2012 (IEC61000-4-4:2012)
EN 61000-4-5 :2014 (IEC61000-4-5:2014)
EN 61000-4-6 :2013 (IEC61000-4-6:2013)
EN 61000-4-11:2004 (IEC61000-4-11:2004)
Environmental Aﬀairs:
Ar cles manufactured on or a er the Date of Issue of this Declara on of Conformity do not contain any of therestricted substances in concentra ons/applica ons not permi ed by the RoHS Direc ve.
Carl Haapaoja, Director of Quality Assurance

Contents

page 31WebDAQ 316 User's Guide

Measurement Compu ng Corpora on
10 Commerce Way
Norton, MA 02766
Phone: 508-946-5100
mccdaq.com/support

page 32