Fnirsi SG-003A & SG-004A Signal Generators - Page 1
Forum section: electronics / testgear

author: DaneLaw
author_rank: Frequent Contributor
timestamp: October 08, 2022, 08:36:38 pm
content: SG-003A & SG-004A Signal generators/process meters.SG-003A Blue (0.1% +0.005)SG-004A Yellow (0.02% + 0.005)Manual.SG-003Ahttps://www.mediafire.com/file/mvequ9hyt09a282/003A%25E8%258B%25B1%25E6%2596%2587%25E8%25AF%25B4%25E6%2598%258E%25E4%25B9%25A6V0.2.pdf/file?SG-004Ahttps://www.mediafire.com/file/prhgpn4hhz6t4fh/004A%25E8%258B%25B1%25E6%2596%2587%25E8%25AF%25B4%25E6%2598%258E%25E4%25B9%25A6.pdf/file?A feature-walkthrough from Kerry Wong.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: October 08, 2022, 08:39:46 pm
content: Decided to purchase one of each at AliExpr's latest sale from two different stores, while the SG003A (blue) has arrived the more expensive SG-004A (yellow) hasn't - and not gonna arrive, as I sadly landed a dishonest Fnirsi-store/seller, that uses the old trick with an excuse about "quality-problems" after I paid.And after some time, give an option to refund by PayPal.Tried to explain it ain't an option, as the "price" people from Europe pay, also incl. VAT - so it needs to go through Aliexpress-system for those buyers to get their 25% VAT back..and it seems he wouldn't do that, as it will hurt his store, so instead put a fake tracking from Serbia of all places with an old timestamp, in an attempt to steal the money as the Aliexpress-system seems to accept that, even though Im in Denmark with my danish address, - and I as a buyer will be in limbo until the AliExpr. systems after a few weeks (or months) hopefully let me dispute it. - but that's "Aliexpress" in a nutshell, and something you need to tolerate if you wanna use that platform.Usually, dishonest sellers will put some other persons tracking from your country, so it actually looks like it's heading your way when checking it, - I guess the tracking database these rancid sellers are using, was out of danish relevant tracking details.it was the Aliexpress Store. "El Kitchen Store" (rancid fellow, stay clear of that store) even used a tracking that says delivered in Serbia before I made the purchase.-Aliexpress system is horrendously undermined if rotten sellers can use other peopples tracking that is "old" and already says delivered to another country (Serbia" before I made the purchase.and the system won't let me dispute it... it says to wait 10 days... (I did) and now it says.. I shall need to wait and there needs to be at least 15 days of no activity on the tracking, and its hilarious as there hasnt been any movement on that tracking since 23 Sep where it was delivered to somebody in Serbia.https://parcelsapp.com/en/tracking/SY15030779787Im in Denmark, how this Aliexpr.-system let him use an old dated tracking to Serbia is beyond me. (certainly not doing Fnirsi any benefits letting the most rancid stores on Aliexpress do this bs to customers)The other Fnirsi SG-0003A (blue vers.) was purchased at Dylan Selection Store - and that was a pleasant experience, to a strong sale price, topnudge buying experience.So far I'm quite impressed with how polished and well-built this product is from Fnirsi. (if they actually are making it, and it aint a rebrand from some third-party)It feels well-built not least with the price in mind and it's a sexy little gadget. with tons of features.. there are a few spelling mistakes in the UI, and missing letters in certain places but it doesn't have that Frankenstein feel that I often have seen from Fnirsi, where it comes across as a mashup from other parts at the local market.It's a nice little gadget for the price.It will lid up the buttons to indicate what mode/feature you're in.

author: Cpuch22
author_rank: Contributor
timestamp: October 26, 2022, 03:04:23 am
content: I purchased the SG-004A. Below are some photos of the teardown. It's pretty cool.

author: TheNewLab
author_rank: Frequent Contributor
timestamp: November 07, 2022, 05:44:22 am
content: wow! looking at the SG-004A inside is like looking over New York City, while the inside of the SG-003a is more like..the Bahamas? Just to add temp?

author: NoMoreMagicSmoke
author_rank: Regular Contributor
timestamp: June 08, 2023, 03:45:11 am
content: I purchased an SG-004A. Testing it out it appears to have a significant amount of (likely) thermal drift after first powering on. Once it stabilizes it appears to meet its specifications, but until it stabilizes, it is about an order of magnitude lower than is allowed by it's accuracy specification.

author: ozkarah
author_rank: Regular Contributor
timestamp: July 02, 2023, 02:52:48 am
content: According to the manual device can be controlled under MODBUS Slave mode and at the end of the manual there are tables of MODBUS functions.But, the manual does not describe how to connect the RS485 wiring. Does anyone know how to communicate and control this device using MODBUS (RS485)?

author: bigmavr
author_rank: Newbie
timestamp: July 17, 2023, 02:38:59 pm
content: Quote from: ozkarah on July 02, 2023, 02:52:48 amwhen the device is turned on, connect the connector, a new com port will appear. You can connect through it (RS-232)

author: Lachin012
author_rank: Regular Contributor
timestamp: August 25, 2023, 09:04:21 pm
content: I asked Fnirsi a question to them by mail, they answered that you yourself must find a program for communication with SG-004A, I could not find the program, I still did not understand what program was in question, maybe you know which program you need to install for connection with SG-004A?sent me this pdf.

author: ozkarah
author_rank: Regular Contributor
timestamp: September 07, 2023, 12:58:26 pm
content: Great share, thanks.The problem here is they use non-standard function codes 101 and 102 for ModBus.I couldn't find a ready-to-use ModBus Master application capable of sending these codes.Probably I will have to write some program for it.

author: ivo
author_rank: Regular Contributor
timestamp: November 23, 2023, 11:31:06 am
content: You can tell what ref it uses? Looks like maybe it's the AD D1S chip?

author: NoMoreMagicSmoke
author_rank: Regular Contributor
timestamp: November 26, 2023, 05:37:04 am
content: Quote from: ivo on November 23, 2023, 11:31:06 amD1S chip is most likely the DAQ.https://www.analog.com/media/en/technical-documentation/data-sheets/ad5426_5432_5443.pdf

author: Electrump
author_rank: Contributor
timestamp: January 20, 2024, 05:08:05 pm
content: The specs look pretty similar to me. I think a company would not have two similar devices on the market at the same time. Can someone please explain what is the difference between these two devices purpose-wise?

author: DaneLaw
author_rank: Frequent Contributor
timestamp: January 20, 2024, 06:37:49 pm
content: Quote from: Electrump on January 20, 2024, 05:08:05 pmSG003A and SG004A..the main difference is tolerances... SG004A is rated at 0.02% (+5)This YouTube channel has numerous good videos about these two devices and also looks at the added features, not least TC standards.Good low key YT channel, that comes across as honest & objectivehttps://www.youtube.com/@three-phase562/search?query=sg004aI only tried the SG003A which for the last 1½ year, been a very pleasant experience, not least from a Fnirsi product.. like it a lot to the point that I been looking into getting the SG004A but the pricejump from 45US to 120US is a tad (incl. EUVAT), and most of the added SG004A-features, are not that relevant to my usecases, and accuracy on my SG003A is already better then I have tools to validate.LIke the frequency tools, and being able to rig that up to your heart's desire.Quite handy when working with lasers & LEDs to have these standards in a small handheld unit.

author: arturmariojr
author_rank: Contributor
timestamp: May 06, 2024, 12:57:54 pm
content: Does anybody know what is the mode XMT of Fnirsi SG-004A?Does it make this device to be a current controller, like Fluke 789 on simulation current source, when you must connect a power supply to its input and the load to output and it will controll the sinked current by load?Best regardsArtur

author: DaneLaw
author_rank: Frequent Contributor
timestamp: May 06, 2024, 09:03:10 pm
content: Quote from: arturmariojr on May 06, 2024, 12:57:54 pmI don't have the 004A, only purchased 003AThough' the manual states (Passive XMT)QuoteManuals.SG003Ahttps://img.wqdres.com/res/0/20231229/f5e538de025c4a0293ece76f956df138.pdfSG004Ahttps://img.wqdres.com/res/0/20231229/88578d747c8e46bc8625bde800fc921b.pdfHave you checked the "Three Phase" YT-videos [linked in #12] I do recall he went through the different use-cases on most of these extensive test-features.

author: Mike1233
author_rank: Newbie
timestamp: May 11, 2024, 12:08:16 am
content: Quote from: arturmariojr on May 06, 2024, 12:57:54 pmI am new with the Fnirsi SG-004A but i have tried the option XMT.I have a device for measuring the volume of a tank. It uses a pressure sensor from 4-20mA. It has 2 wires.If i measure the output for the connectors measures 21,3V DC.If i connect the SG-004A on the sensor input, with the setting XMT, and change the mA output it shows that the volume is changing.If i use the "normal" output mA then nothing happens.

author: LastManStanding
author_rank: Newbie
timestamp: May 12, 2024, 05:09:49 pm
content: Hi there,I'm experiencing some unusual behavior with my SG-004A. I'm unsure if my device is faulty. There is a consistent fluctuation in the output voltage, around 2mV. The voltage gradually decreases, then quickly rises again, resembling a sawtooth waveform. Can someone verify if they are experiencing similar behavior with their SG-004A?

author: Alberto Arias
author_rank: Newbie
timestamp: June 19, 2024, 07:02:02 pm
content: Quote from: arturmariojr on May 06, 2024, 12:57:54 pmHello Artur,When you use the SG-004A to generate mA, you have two options:1.- You select OUT mA option. Your SG-004A powers the 4-20mA loop. You even have the option to use either 24V or 12V (the latter option uses less battery power)2.- You select OUT XMT option. Your SG-004A doesn't power the 4-20mA loop. Either the equipment receiving the 4-20mA signal feeds the loop, or you need to use an external power supply.Some other process calibrators that I've used in the past describe those two modes as active/pasive, or source/simulate.Best regards,Alberto

author: 4thDoctorWhoFan
author_rank: Regular Contributor
timestamp: June 19, 2024, 07:13:02 pm
content: Quote from: LastManStanding on May 12, 2024, 05:09:49 pmYes, I have lots of fluctuations with my 004 also. I seem to have more than 2mv of fluctuation. Because of this, I don't really use it anymore. I should have returned it, but I didn't. A also have a LB01A which is rock solid.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: June 19, 2024, 10:24:38 pm
content: Quote from: 4thDoctorWhoFan on June 19, 2024, 07:13:02 pmCan you show an example with your unit?

author: 4thDoctorWhoFan
author_rank: Regular Contributor
timestamp: June 20, 2024, 10:27:39 am
content: Quote from: DaneLaw on June 19, 2024, 10:24:38 pmI should be able to give you an example. Hopefully I will have time this weekend.

author: Phil1977
author_rank: Frequent Contributor
timestamp: June 20, 2024, 12:00:03 pm
content: Is it this behavior?I never cared to much about this. Around 4mV P2P at 5V output voltage is less than 0.1% relative and less than 0.02% over the output voltage range.

author: black6host
author_rank: Contributor
timestamp: June 20, 2024, 02:18:56 pm
content: Pardon my ignorance but could someone please give me some use cases for this device? I mean I'm sure I need one, I just don't know why yet

author: DaneLaw
author_rank: Frequent Contributor
timestamp: June 20, 2024, 02:38:03 pm
content: Quote from: black6host on June 20, 2024, 02:18:56 pmYou have a YT link in #12 - go there.

author: Phil1977
author_rank: Frequent Contributor
timestamp: June 20, 2024, 02:56:07 pm
content: It´s a so called process calibrator - and for some people the swiss army knife of control equipment:1: Industrial process control:- You connect a mess of different branded sensors, actuators and control loops. For system analysis / finding errors you use the SG to simulate critical sensor values and/or readout the sensors. Especially the SG04 is also somehow capable to convert between different sensor types - so e.g. if your flowmeter has a frequency output and your controller needs a 0-10V input you can use the device to translate between different analouge interfaces2. Lab work: It´s just a quite handy current, voltage and PWM source. For low voltages and currents its better than using a lab power supply

author: black6host
author_rank: Contributor
timestamp: June 20, 2024, 03:07:53 pm
content: @Phil1977That's what I thought, industrial control. Not having worked in that environment I'm not familiar with it. The youtube video in reply #12 was great for showing what it did and accuracy but not what it might be used for. Thank you for answering! Cheers!

author: LastManStanding
author_rank: Newbie
timestamp: June 22, 2024, 03:28:46 pm
content: Quote from: Phil1977 on June 20, 2024, 12:00:03 pmNo, I don't mean noise. It's a slow voltage drop of 2mV (within ~23 seconds) followed by a rapid increase of 2mV (1 second). This results in a sawtooth profile in the recording. Additionally, the device heats up quite quickly, causing an additional deviation of +1.5mV/+1°C. This makes it hardly usable as a reference, and the values are outside the specifications (0.02% +0.003). The manufacturer did not respond to my inquiries, which is unfortunately the usual approach for many Far Eastern manufacturers. Produce, sell, forget... But this is also a reason for the low prices.I returned the device and received a refund. I assumed that this phenomenon was a defect in my SG-004a. For that reason, the money wasn't worth it to me.

author: Phil1977
author_rank: Frequent Contributor
timestamp: June 22, 2024, 03:41:29 pm
content: I think I know this "feature": Once I tried to calibrate the SG04 itself - as far as I remember in current mode. The current was slowly *increasing* and then jumped back a few uA. I think the SG04 is drifting quite a lot with temperature but it has an internal compensation based on its NTC. It seems like the readout of the NTC isn't smooth, so that the temperature compensation is done in steps and leads to this "sawtooth" profile.In my case this behaviour was still in the tolerance range. Anyhow, such a €100,- device should never be seen as a rock stable absolute reference. For precise calibrations I´d always additionally connect a trustable DMM. But for checking what happens if e.g. if a sensor runs away the SG04 is really nice.

author: gigotpendu
author_rank: Contributor
timestamp: September 14, 2024, 08:12:27 pm
content: Kind of new to the boards use so I pre-apologize for any infractions.Have a FNIRSI SG-004A that I got as a present. Started playing with it and rather liked what I saw. As I do with new gear I generally update firmware to make sure I'm up to speed on discussions. Big mistake as I seemed to have bricked it. I followed the FNIRSI directions from their web which is actually a JPG file...waited what I thought was a reasonable time and nothing... nada. Tried re-jacking into system several attempts...but nothing. I let it set for a few days jacked back in and actually got connected.. retried with same file and failed again. When it fails there's no immediate second reconnect... almost like power must run down... havent tried 3rd attempt ill let it run down a while... again. Opened the unit and don't see alternate programming port like the TinySA Ultra's.I have helped others unbrick other Chinese produced products, like the TinySA Ultra, using the processors utility STM. Does anyone have any idea on unbricking this pretty good piece of gear? Appreciate any ideas... pre thanks

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 15, 2024, 06:48:02 am
content: I really have no idea if it´s a repeatable solution - but look into the following thread:https://www.eevblog.com/forum/microcontrollers/can-i-program-a-w25q80dv-in-circuitIn summary: I also bricked my SG04 by a firmware update. Then I disassembled it to try to connect to the UART-interface. After removing the display from the PCB I connected battery and USB and surprise: The USB-Flashdrive appeared again and I could flash it with the .bin file. Since then everything is working again.

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 17, 2024, 07:58:37 am
content: Just FYI: I´ve just got feedback from a passive forum member that flashing the SG04 from V2.7 directly to V2.11 seems to brick the device.His solution was also to make the flashdrive reappear by some disassembly and then flashing to V2.9 before going to V2.11Version V2.9 is available at the following link provided by FNIRSI:https://www.mediafire.com/file/2p27blzirvvnvce/SG-004A_V2.9%25281%2529.bin/file

author: gigotpendu
author_rank: Contributor
timestamp: September 23, 2024, 02:14:22 am
content: Thanks for the info and it LIVES AGAIN. Whe I first bricked it I fiddled with it for a while and then, throwing up my hands, left it for a few days. When I reconnected to PC in 48-72 hours and waited maybe 15 minutes I got the ding-dong and boot loader folder. I then put in a new copy of 2.11... bricked again. With your help and anothers, I got the headsup on the migration path you cant go right to 2.11 if you have FW below 2.9 which apparently I do. BTW how the heck can you find the FW on the screens... haven't came across that yet.What ever the brick does, it drains the battery and re-powering the HW must wait the battery upcharge unless you disconnect the battery. I did both. Whether the battery dsisconnect was needed is unknown.My fix and maybe its "THE" FixIF your FW is below 2.9 load 2.9 then the latest greatest which at this time is 2.11.Thanks all

author: gigotpendu
author_rank: Contributor
timestamp: September 23, 2024, 02:42:53 am
content: Phil, thanks for the heads up on the 2.9 first that did it.

author: Mike1233
author_rank: Newbie
timestamp: September 24, 2024, 08:10:58 pm
content: I also installed V 2.9 and then 2.11.Did not have any problems.

author: Aldo22
author_rank: Super Contributor
timestamp: November 13, 2024, 03:28:24 pm
content: Does the SG-003A have any (general) use for a hobbyist who already has an AWG, a DPS-150 PSU and relatively accurate DMMs?I've seen all the videos on it, but I still don't get it.Yes, you can convert voltages to frequencies, for example, but for what purpose do I need that?Does anyone have a scenario that justifies the purchase of this device for non-professionals?It's cheap, it's kind of tempting, but I should recognize some purpose for myself before I order it.Thank you.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: November 15, 2024, 03:27:55 am
content: Quote from: Aldo22 on November 13, 2024, 03:28:24 pmI like mine, to the point that I wondered about also getting the SG004A (0.02%) Do value having volt, mA, and various aspects of frequency control in a small handheld form factor and you can use it to calibrate or check low-count devices, and you can set up crude programs.. its surprisingly feature-rich for a "process meter".But It ain't living up to its tolerances, throughout its full span..The conversion factor is just a linear relationship, where you can lock fx a given input to create the other.I use SG003A for many things, not least crude high powered lasers.. where many run on analog or pwm controlled drivers, and the programs, and stepping are useful with fx 20W RGB laser module,but even just playing around with fx current clamp to check minute single-digit mA current values.. works well to see how accurate a given meter is.. even though SG003A got a far from a so-called "clean output".The last +2 years.. surprised me how much I use it, do value having a current/voltage, frequency-source in such a small handheld battery form-factor.,9mA into an LEDwith clamp.but if you don't have any specific use cases.. save your money, as there will always come new items and there are limits to what kind of accuracy you gonna get, at these prices..Its not a new item, I got mine in summer 2022 and the prices today haven't gone down, vs what they cost in mid-2022, that today seems higher.The YT channel "three phase" have many good videos about these handheld signal calibrators and also examples industrial usecases.When I compare my SG003A to other handheld process calibrators.. that can go down to single digit uV and gives granular 1uV control, there is a quite a difference, but that goes without saying, as the prices are also in another ballpark... worth noting the SG003A doesn't have resistance..

author: Aldo22
author_rank: Super Contributor
timestamp: November 15, 2024, 10:23:19 am
content: @DaneLawThanks for the detailed answer!The decision would be easier for me if I didn't already have the DP-150 as a small, portable V/A PSU.Although it doesn't get into the lower mV/μA ranges, it sems more accurate in the mV range.I found thislistto compare.In the attached picture you can see that the DP-150 is more accurate from e.g. 50mV to 250 mV (up to almost 1V, after that the SG-003A is also accurate).Well, maybe accuracy is not the main purpose of the SG-003A.I still find it hard to say: “Yes, I need it”.P.S. Did you get anywhere with MODBUS?

author: Aldo22
author_rank: Super Contributor
timestamp: November 15, 2024, 03:44:50 pm
content: Any resistance was futile. I ordered it for 33 GBP.Maybe I'll find a use for it.A German proverb says: “Der Appetit kommt beim Essen”

author: HLMBDD
author_rank: Newbie
timestamp: November 25, 2024, 09:33:57 pm
content: Hi,i update my SG-003A to V4.3 and it stops booting, can you please help me to fix this problemand if you could to share previous firmware versions prior than V4.3when i connect it to laptop i steal can see the bootloader folder i tried to reload the bin file again and i get Errapp.txt file created in the bootloader folderthanks.

author: Aldo22
author_rank: Super Contributor
timestamp: December 01, 2024, 01:46:03 pm
content: Has anyone gained any deeper insights into the remote control of this device (Modbus)?I'm struggling to understand the documentation.

author: ozkarah
author_rank: Regular Contributor
timestamp: December 07, 2024, 12:54:27 am
content: Quote from: Aldo22 on December 01, 2024, 01:46:03 pmI managed to do it using serial connection from PC

author: Aldo22
author_rank: Super Contributor
timestamp: December 07, 2024, 07:46:01 am
content: Quote from: ozkarah on December 07, 2024, 12:54:27 amGreat!Can you share some code with us or explain how you managed the communication?How do you set/read values? V and mA would be enough for me.

author: Aldo22
author_rank: Super Contributor
timestamp: December 10, 2024, 05:36:12 pm
content: I just found out that it is better to calibrate the SG-003A on a lower range than the specified 6mA.That way you get remarkable accuracy.Attached is a picture with 5µA, i.e. up to nA accuracy.

author: bitovod
author_rank: Newbie
timestamp: April 10, 2025, 11:12:05 pm
content: Hi, I have the same problem - after flashing FW 4.3 there is only a black screen, SG-003A can only boot into bootloader (if I disconnect the battery). I don't have any other FW that I could upload there, did you manage to solve the problem somehow?

author: Mike1233
author_rank: Newbie
timestamp: April 21, 2025, 08:32:29 pm
content: Is it possible to adjust the brightness of the screen?I use the SG-004A also outside and then if the sun is a bit to much you see nothing on the screen.

author: Aldo22
author_rank: Super Contributor
timestamp: April 21, 2025, 08:55:19 pm
content: Quote from: Mike1233 on April 21, 2025, 08:32:29 pmI have the SG-003A and there you can set it in the general settings under “In_Ac_Op” -> “Light”.

author: Mike1233
author_rank: Newbie
timestamp: April 22, 2025, 04:24:02 am
content: Quote from: Aldo22 on April 21, 2025, 08:55:19 pmI will have a look, later this day.Thank you.edit.That was the place to change it. It was already to the maximum.I still find it a bit dim in daylight. But i have to deal with it i think.Thanks.

author: bffargo
author_rank: Regular Contributor
timestamp: April 25, 2025, 05:38:21 pm
content: Just received a SG-004a as my last Ali purchase before the US tariff's started. Mine came with v3.0 firmware. Latest on their web site is only 2.11.I'm appalled at the lack of UI "polish" on this device, as well as a number of more recent Fnirsi devices, especially in the configuration screens. In the past they seemed to be much better.Had Zoyi had a similar device / pricepoint, I would have gone with that instead. But this should suit my very limited needs of producing low voltage / amperage with highly detailed level control for configuring/testing other devices.

author: mt1
author_rank: Newbie
timestamp: May 05, 2025, 05:12:22 pm
content: Quote from: Aldo22 on December 07, 2024, 07:46:01 amIt is possible for example by small program commixhttps://www.dcmotorkeya.com/phoenix/admin/download?fileId=mefpAUvcKTCt&dp=GvUApKfKKUAUIn my case it sent me firmware version 0030 and it looks similar to V3.0 on my SG-004A start screen.

author: LampHead
author_rank: Contributor
timestamp: May 14, 2025, 06:38:37 am
content: Hi everyone,Just wanted to share another SG-004A firmware update gone wrong.I bought my unit at launch back in 08/2022, and it had been working perfectly without any issues. Yesterday, I decided to update the firmware. I followed the steps, dropped the .bin file into the drive, but there was no magic reboot. I had to unplug the unit from USB and turn it on again manually. The unit started up, but with a very different interface—it looks like the upgrade failed and it reverted to a base firmware. I tried both available versions, 2.9 and 2.11, and got the same result. Following another user's advice, I ran a Modbus query to check the version, and it returned 2.4.Has anyone else had the same problem?

author: DaneLaw
author_rank: Frequent Contributor
timestamp: May 15, 2025, 04:43:42 am
content: Quote from: LampHead on May 14, 2025, 06:38:37 amSeems quite a few people had issues upgrading the SG004A.I only have the SG003A, so Im not in the same boat, and made one firmware update around ½ to a year ago, also a drop to rootfolder and worked as expected - which mainly corrected some spelling mistakes.Have you tried contacting Fnirsi?... Just make clear to them that you wanna talk with a technician, as the official Western listed fwhttps://www.fnirsi.com/pages/manuals-firmwaresare creating issues for numerous users in this thread.Can sometimes also be helpful to link to this EEVthread, so they can see that its more then just you.

author: LampHead
author_rank: Contributor
timestamp: May 15, 2025, 08:25:42 am
content: Hey mateYeah, Ive tried their online chat to no avail, and later sent a message to service@fnirsi.com explaining the situational. Normally i wouldn't expect them to be quick in replying. Will re-post once i hear from themThanks

author: bffargo
author_rank: Regular Contributor
timestamp: May 20, 2025, 05:53:25 pm
content: It's weird too that my new SG-004A purchased last month from AliExpress arrived with V3.0 firmware, yet the latest on Fnirsi's site for years is only 2.11 and what is causing everyone problems. One would hope a copy of 3.00 is available that they can send you.

author: LampHead
author_rank: Contributor
timestamp: May 30, 2025, 03:08:48 am
content: OK, FNIRSI got back to me with new firmware, which installed successfully. On boot-up, the screen displays V3.0. The downside for me is that, since my device version is quite early, there's a possibility they changed the screen down the line, and I ended up with inverted colorswhich isn't ideal.

author: bffargo
author_rank: Regular Contributor
timestamp: May 30, 2025, 04:03:50 pm
content: That makes sense why they may not have posted v3.0 yet to their web page then. Wonder if others would like to have it but knowing the limitation it has?

author: LampHead
author_rank: Contributor
timestamp: May 31, 2025, 12:32:39 am
content: To clarify, I don't expect many people to have this problem. I had the screen inverted on the first firmware upgrade (v2.9), and it never reverted to the original color scheme, regardless of the firmware version. The manufacturer might have changed the screen type in early production. Either way, it's better for everyone to be aware of this.Interesting fact, I've tried to re-flash v2.9 and on modbus fw version query still get 2.4, but on version 3.0 get the correct response

author: Phil1977
author_rank: Frequent Contributor
timestamp: June 05, 2025, 09:49:14 am
content: Just updated my device to V3.0 - thanks for uploading the file!My hardware revision (labelling on the battery side of the PCB) is X18. The first update failed and I had to remove the PCB and disconnect the display again to get it back into USB-drive-mode. After copying the image file a second time it works again, reports V3.0 at bootup and I haven't found any inverted colours so far.

author: LampHead
author_rank: Contributor
timestamp: June 14, 2025, 03:51:21 am
content: No problem Phil, thanks for the update

author: tutochkin
author_rank: Contributor
timestamp: June 21, 2025, 02:50:21 pm
content: I have ordered and am waiting for delivery of Fnirsi SG-004A.In the meantime, IMHO, the best video with examples of working with Fnirsi SG-003A. Including the current loop.https://rutube.ru/video/25261a90945c9713e05c666bffb43c48/

author: Mike1233
author_rank: Newbie
timestamp: June 21, 2025, 04:19:27 pm
content: Quote from: tutochkin on June 21, 2025, 02:50:21 pmThis YouTube channel has also a couple of tests and comparising video's.https://youtu.be/fXANvAbz3RI?si=S65ufFIeE6afgysu

author: Alex_98
author_rank: Newbie
timestamp: June 30, 2025, 12:14:04 pm
content: Hi everyone had someone success with writing some of the other registers via modbus for example output Voltage 4.5V. I tried it over a hundred times but i only succeded with writing the output modes.

author: tutochkin
author_rank: Contributor
timestamp: July 03, 2025, 05:33:05 pm
content: My gadgets have arrived. While I was waiting for 004, I bought 003 (he got there even faster in the end). Now I can compare the work1. The charging cable and charger are no good2. Devices must be calibrated, it is simply not possible to use them without setting them up. The settings of the devices are different - both in reference points and in bit depth (in the photo 0/01/24 mA - 003 and 6/12/18mA - 004). But even after setting up, there is no 100% quality outside the reference points.3. Although the devices have been on the market for a long time, the problem with the modbus connection has not been solved

author: Alex_98
author_rank: Newbie
timestamp: July 04, 2025, 09:36:03 am
content: At the moment i am doing research on how to reverse engineer the firmware using ghidra and searching for possible improvements to be made on the modbus registers.Before that i was trying to map the registers and searching for firmware lockouts. Using AI gave me some hopes to bruteforce the registers but it seems the mentioned lockouts are problematic for mapping the registers.I made a table with raw data from the bruteforce attempt. I did some test with the data registers and as expected the response is bound to the state of the device. I could force a static response by some of the unknown registers with via uart but with no context to the received data its of no use to further following this approach.I will give u guys an update on the project, but i will not post any kind of sourcecode because of copyrights.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 04, 2025, 10:25:16 am
content: Quote from: Alex_98 on July 04, 2025, 09:36:03 amI'm really confused why people spend endless hours into reverse engineering stuff from one of the most crappiest brands there are. The way fnirsi lies in their specs and use weird averaging to hide the deficiencies of the hardware should be enough. On top of that, there are plenty of negative reviews about the fnirsi stuff. Apparently the combination of "cheap" and a box that looks good is enough to keep on fooling a whole lot of people. If you want to reverse engineer some product to make it better, there is plenty of reasonable quality hardware that can be improved by better firmware. Or even better, contribute some of your effort to one of the many open source projects that are struggling to survive. Then you can skip the whole "reverse engineer" step and start contributing right away.

author: tutochkin
author_rank: Contributor
timestamp: July 04, 2025, 10:36:22 am
content: There is also such a project for working with the device. Unfortunately, I couldn't use it.https://github.com/wirenboard/fnirsi-sg004a/blob/main/README.mdDoctorandus_P, Are there any examples of devices similar to 004 that you think you should pay attention to?

author: Aldo22
author_rank: Super Contributor
timestamp: July 04, 2025, 02:27:41 pm
content: Quote from: Doctorandus_P on July 04, 2025, 10:25:16 amI have a FNIRSI SG-003A and am very happy with it.Which device would you recommend for 45€ or less?

author: DaneLaw
author_rank: Frequent Contributor
timestamp: July 04, 2025, 03:41:36 pm
content: Quote from: Aldo22 on July 04, 2025, 02:27:41 pmIts usually "Fnirsi's" persona-non-grata reputation from some of their attempts to making oscilloscopes, that seems to spill over and taint people's bias on anything coming out under a Fnirsi label..Gotta handful of Fnirsi products, and with the price in mind.. it's been a positive experience... even their 50 $ PSU.. it was more handy than I thought to have a display and being able to visualize some of the more advance features in these programmable sink loads, that are quite packed with different test scanrios that I ain't familiar with..https://tinyurl.com/2sw9bxrjAlso purchased a USB meter 3 years back, and back then in 2022 a USB meter that could both read and trigger PD3.1 protocols was not cheap, and at 37 $ with BT (FNB58) incl. 25% EUVAT was weirdly good value..https://tinyurl.com/mtbvfs29I only got the SG-003A around the time when it was released but I use it often.. I appreciate all the features it holds and being able to program V, Amp, and Frequency to your heart's desire.Im not familiar with any other product int he same pricebracket, that gives the same featurerich palette of settings.. most of the other are rudimentary Volt & Amp process meters.There are some models from OHR, but they are Chinese domestic sale only.. contacted the company on Taobao as I had a phase where I liked to purchase items that we don't see on our latitudes, and they would gladly sell at quite attractive prices, but they had no interest in any sell at all to foreign addresses, only to domestic CN addresses.Optained one by a third-party seller on Aliexpress, like a year back... its this onehttps://tinyurl.com/3xu58rdtit goes down to 1 microvolt tolerance, and also got frequency, volt, amp, and resistance nd programmable ablelities.. it got good tolerance for temperature with its fine voltage control and comes with CJC ext calibration. (USB3 dongle)Manualhttps://www.eevblog.com/forum/testgear/ohr-multifunction-process-calibrators-(ohr-c03)/?action=dlattach;attach=2472177(from the corresponding thread)Its a multi-function-tool from an OEM vendor in China [Hongrun Precision Instruments) who is making industrial transmitters, meters, pressure sensors, PID controllers etc (as far as I can tell).https://en.hrgs.com.cn/Nhrshop/?type=list&category=0&page=3But its a not a product that figures on their English/int. site, only their domestic pagehttps://www.nhrgs.com/ohrshop/?type=detail&id=163Sofar SG-003A been a positive experience, find it ideal for creating rudimentary signals, very convenient to set up, and it holds a charge well..

author: tutochkin
author_rank: Contributor
timestamp: July 08, 2025, 12:20:54 pm
content: The "Convert" function to 004A does not work adequately. Given: measuring the resistance in 004A and converting it to a current output.If you set the settings:Input H = 390 L = 0Output H = 20 L = 0then everything works. But if you askInput H = 390 L = 0Output H = 20 L = 4(current 4...20мА) then the output is 0...20 mA anywayhttps://rutube.ru/video/43b00bad5728239bbfff7ff828d874df/?r=wd

author: ovidiu_BZ
author_rank: Newbie
timestamp: July 16, 2025, 04:21:42 am
content: HELLO.I had the same problem. After the firmware update of the SG-003a failed, the screen remained black and the computer no longer recognized it as a USB disk. The solution is very simple and fast.you must disassemble the back of the device and remove the battery. connect it again via the USB cable to the computer and you will notice that now the computer can detect it as a USB device. connect the battery without removing the USB cable. Press the power button to turn it off. press the power button again and go to the BOOTLOADER disk that just appears in mycomputer, put the SG-003_V4.3.bin file here and hold until the end of the procedure.That's it.

author: williamellison22
author_rank: Newbie
timestamp: July 20, 2025, 05:19:46 pm
content: Has anyone experenced loose connection with the output/input ports?I used mine once to stest against a fluke and the red port is loose and I have to plug in the cable half way for it to work properly.Thank you

author: tutochkin
author_rank: Contributor
timestamp: July 22, 2025, 01:02:33 pm
content: williamellison22,https://rutube.ru/video/bd3dacccffc87d0a52577f21b5e4b43d/?r=a

author: Mike1233
author_rank: Newbie
timestamp: July 22, 2025, 03:52:17 pm
content: I think this is the original video on YouTube.https://youtu.be/XQorHbb1DY4?si=EokAnWgaoFePLikR

author: tutochkin
author_rank: Contributor
timestamp: September 13, 2025, 05:44:42 pm
content: There are few functions available in Fnirsi SG-004A, I bought MR9271PRO signal generator HART protocol Modbus protocol Precision enhancement signal simulation PT100\PT1000\TC.It is now possible to work with Pt1000, HART and Modbus. And in general, the readings of the device are more stable. However, there are also comments on convenience - Fnirsi SG-004A is more convenient IMHO. It's a pity that you can't take the MR9271PRO and put it in the Fnirsi SG-004A case.In addition, the MR9271PRO can make a sinusoid, unlike the fnrsiIf you're interested, here's the documentation for the device. Unfortunately, the official website has not been updated for a very long time....https://drive.google.com/drive/folders/1c4yW7zm3lYu4BDPaS8TA2zIVt4RQmHZ_

author: Lachin012
author_rank: Regular Contributor
timestamp: September 30, 2025, 11:12:29 pm
content: Quote from: tutochkin on September 13, 2025, 05:44:42 pmHi! I'm also waiting for my MR9271PRO. Could you tell me what the difference is with the previous model?