Do any of you now any DIN Rail mounted DMM with autorange? - Page 1
Forum section: electronics / testgear

author: CKnop
author_rank: Newbie
timestamp: January 23, 2017, 03:14:59 pm
content: Hi.I am looking for a DIN rail mounted digital multimeter with autorange (8 bit converter with 0-5V, 0-50 is enough).The DMM shall be read be read by a PLC or computer using one of these interfaces: I2C, SPI, RS232, RS485, Modbus, Ethernet or USB.Do any of you know of something like this?Thanks!Best regards,Carsten.

author: Short Circuit
author_rank: Frequent Contributor
timestamp: January 23, 2017, 11:12:27 pm
content: Not DIN rail, but quite close;http://www.yoctopuce.com/EN/products/usb-sensors/yocto-volt

author: forrestc
author_rank: Unknown
timestamp: January 24, 2017, 10:52:23 am
content: Quote from: CKnop on January 23, 2017, 03:14:59 pmYou need to better define 'DMM' and what you hope to gain from autorange.... Or put differently: what are you trying to measure, and do you really need a 'DMM' or just a way to measure that voltage:For instance, if you're just trying to read a voltage via a PLC or computer:There are lots of products out there which will read voltages via one of several protocols. For instance, I sell one (https://store.packetflux.com/sitemonitor-base-unit-ii/) which does SNMP and has add-on modules to read voltages beyond the voltages supplying power to this unit. In this particular case, I read up to around 60V or so with a 10 bit ADC. I've got higher accuracy units in the pipeline as well... And I have quite a few competitors in the marketplace.Most PLC's also have analog input options which might work as well.

author: CKnop
author_rank: Newbie
timestamp: January 27, 2017, 08:44:13 am
content: Thanks for the info. It's not quite what I'm looking for though.I like the yocto-volt, but the issues that concerns me are the relatively small input resistance and the availability of the product (is it on the market for sale in 10 years from now).I'm building a professional test system for use in a LEAN production environment. It means that every product or product series shall have its own test equipment, hence it must be relatively cheap (~2000$) and in a small box with a laptop mounted on top of it.The test system I'm building consists of a few power supplies, relays, PLC/Logic board, communication interfaces, linear actuator controller, in-circuit production programmer and some other equipment.It's much to compact into a small box where most the equipment should preferably be mounted on DIN rails.The DMM I wish for is the U2741A by Keysight/Agilent:http://www.keysight.com/en/pd-1420686-pn-U2741A/usb-modular-digital-multimeter-5-digit?cc=US&lc=engBut it's a little overspect., large, quiet expensive and it's not DIN mountable (but can live with that it isn't).This is actually something like I'm searching for (but it's a bit slow): Carlo Gavazzi - Digital Panel Meters Modular signal conditioner Type USC-DINhttp://www.carlogavazzisales.com/pdfs/controlprod/USC%20DS%20ENG%200804.pdfDMM spec (all of this should apply in the full industrial temperature range):I need to measure a small current ~10µA. But in the system I'm building it can be done by measuring 0,01V over 1kOhm when 10µA is flowing through it.In another situation I need to measure a voltage of around 40 volts but only with 100mV to 200mV precision.I also need to measure a current of about 1mA to 300mA with an accuracy of about +/-1mA. And also 100mA to 1A with an accuracy of 50mA.The measurements shall be read by a computer or PLC.The measurement ranges could simply be some relays and resistor added to the equipment that I control with the PLC/computer.Hope someone knows of a reliable/stable company who make a product like this.

author: ebastler
author_rank: Super Contributor
timestamp: January 27, 2017, 12:47:53 pm
content: Just for clarification: So you don't need any display or control elements in the "DMM" at all? It could be just the sensing electronics, to be controlled and read from the PC, right?(I don't have a solution in mind yet, but having a clear understanding of what's needed might help me or others to think in the right direction.)

author: guenthert
author_rank: Frequent Contributor
timestamp: January 27, 2017, 07:18:21 pm
content: You might want to consider products like the I-7000 series from ICP DAS. On the market for more than 15 years and probably will remain a while longer. Not quite cheap new though, but robust (intended for industrial use). I got a I-7018R on the secondary market for a very reasonable price. Good built quality, galvanic separation and all the jazz. And yes, meant to be attached to DIN rail.

author: Hensingler
author_rank: Regular Contributor
timestamp: January 27, 2017, 07:45:52 pm
content: http://www.advantech.com/products/99c053f2-bac0-439f-aa0d-f8f991026c6a/adam-6117ei/mod_8c5e6ed7-e01a-4235-b2ce-3d0ee6355a38http://www.advantech.com/products/gf-5vtd/adam-4017/mod_170c40f4-e6ac-485e-9df9-1e6ef60f971f

author: forrestc
author_rank: Unknown
timestamp: January 28, 2017, 05:41:31 am
content: Quote from: CKnop on January 27, 2017, 08:44:13 amA full test equipment set per product seems opposite of the LEAN methodology that we use.... We've moved to a rack of PXI/VXI/GPIB/USB driven test equipment which then has a quick-change harness. We can then spare the equipment for much lower cost, and effectively have an entire spare set. Each product gets it's own harness, but the backend test hardware is all the same. This prevents duplication and waste in things like calibrations, and duplicate equipment, etc.. The quick-change harness limits waste on product changeover. In addition, a single test harness can be used to validate the entire system by plugging the harness into the test system then running a special test program which tests the tester using the test harness.That said:If you're putting a laptop on each of these systems, then I think another option would be to look at running the automation in the laptop, (Labview?), and then focus on generic instruments which plug into windows. Things like a Diglent Analog Discovery, or a USB attached DMM, etc.Also, don't discount the analog inputs built into the PLC's themselves. All of your analog needs can be easily read with the inputs of a standard ADC with a bit of simple resistive divider and/or a amplifier (something like a uCurrent). For instance, automation direct sells the koyo click PLC's which have 0-10V adc inputs as an option - either on the main unit or on an expansion. There are larger units (different series) with more features as well.