# Signet S3L signal testing and simulation/generator?



## MotoGP1199 (Aug 11, 2014)

I work with signet flow meters a lot and they use a S3L frequency signal. I have always been able to troubleshoot a faulty sensor one way or another without actually testing the signal. Either by using an extra sensor or extra meter. I was wondering if there is a way to test the signal with a standard meter and also generate/simulate a signal. I was hoping to simulate a signal (any signal) just to test that a meter is receiving a signal. Similar to how you can use a 9v battery and resistor to simulate a 4-20ma signal for a quick test. I can't find too much on S3L digital frequency as it seems to be mostly proprietary to signet. Sometimes I'm at a job without extra of either(sensor or meter) and it would be nice to have this info available. I'm at home now and just started thinking about how to test or simulate the signal. Just looking at the sensors I would assume its some type of square wave frequency they generate. Measuring the frequency seems like it might be straight forward with a DMM, I'll have to check that out next week.


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## splatz (May 23, 2015)

This is one of the things that I like about 4-20ma, everything you need to do can be done with simple tools. 

Would you be able to crack the S3L encoding with a DMM or would you need an oscilloscope? Depending on what you find it's possible you could hack a signal generator but it seems like a longshot it would be cheaper than carrying a spare sensor. 

It looks like they do make a diagnostic tool 



http://spectechind.com/Documents/signet-misc-0250-data.pdf


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## gpop (May 14, 2018)

only $300 bucks and probably as temperamental as hart









GF Signet 0250 USB to Digital (S3L) Configuration / Diagnostic Tool


GF Signet 0250 USB to Digital (S3L) Configuration / Diagnostic Tool




valvesandinstruments.com


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## MotoGP1199 (Aug 11, 2014)

I looked at that tool online and actually downloaded the software for it. It supports one of the meters I use but not the typical sensors. I'm curious if it will actually read the standard signet 515 sensors even though it is not specifically listed for it. As it(standard 515 sensors) generates its own S3L signal but doesn't have an onboard processor like some of the sensors it does support. I'm not sure the list they have for sensors is only for the programing and setup. From the specs it looks like it will read S3L, I may have to call Signet on monday. Although I can buy a small 515 sensor for cheap or might even be able to get an old working one from someone.


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## gpop (May 14, 2018)

Depending what you require to troubleshoot you can probably do it with a $5 arduino.

(copied so credit to who ever worked this out at automationdirect)
The S3L protocol is TTL-level single-wire bus. The sensors are powered by 5VDC, and the data line is referenced to ground. It communicates at 9600 bps, with 7 data bits, no parity, 1 stop bit, and no flow control. 

Its meant to be a message request protocol rather than the sensor constantly sending data. So the display requests the data. 
From a quick google search i know they can intercept and read data between the sensor and display. With a little more research you may be able to find someone who can worked out the rest,


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## splatz (May 23, 2015)

gpop said:


> Depending what you require to troubleshoot you can probably do it with a $5 arduino.
> 
> (copied so credit to who ever worked this out at automationdirect)
> The S3L protocol is TTL-level single-wire bus. The sensors are powered by 5VDC, and the data line is referenced to ground. It communicates at 9600 bps, with 7 data bits, no parity, 1 stop bit, and no flow control.
> ...


Nice find! 

from Community

I think what that's saying is it's just a serial device. Supply 5V power to the sensor, (you can do this with a wall wart, a phone charger, or even a USB port) and you can make a serial adapter to talk to a regular serial port on your PC. The adapter would have to take the transmit from the sensor to the receive on the PC serial port, and ground to ground as signal reference. Set the serial port parameters as indicated in Windows, and you should see the ASCII stream from the sensor in any terminal program on the PC.


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## MotoGP1199 (Aug 11, 2014)

gpop said:


> Depending what you require to troubleshoot you can probably do it with a $5 arduino.
> 
> (copied so credit to who ever worked this out at automationdirect)
> The S3L protocol is TTL-level single-wire bus. The sensors are powered by 5VDC, and the data line is referenced to ground. It communicates at 9600 bps, with 7 data bits, no parity, 1 stop bit, and no flow control.
> ...


Great find !!!


splatz said:


> Nice find!
> 
> from Community
> 
> I think what that's saying is it's just a serial device. Supply 5V power to the sensor, (you can do this with a wall wart, a phone charger, or even a USB port) and you can make a serial adapter to talk to a regular serial port on your PC. The adapter would have to take the transmit from the sensor to the receive on the PC serial port, and ground to ground as signal reference. Set the serial port parameters as indicated in Windows, and you should see the ASCII stream from the sensor in any terminal program on the PC.


Awesome guys, this looks like a little more work than I was originally looking to do, BUT this looks like a fun project and I might be able to build a stand alone tester (at least to verify simple items). I have a little bit of experience with Arduino on my 3d printer so I'm going to look into this.


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## splatz (May 23, 2015)

If you do it with your PC, there's no arduino needed, it's a 20 minute $20 project!


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## emtnut (Mar 1, 2015)

Agree with splatz. If the TTL level is needed, just use a convertor rs232 to TTL are common.

Any Terminal program will show the data stream.
If you can get a copy of the protocol, then you could send out requests to the transmitter too.

If you only have a USB on your laptop use something like this








USB to RS232 / RS485 / TTL Industrial Isolated Converter


USB to RS232 / RS485 / TTL Industrial Isolated Converter Offers conversion from USB to RS232, RS485, and TTL (UART) Adopts original FT232RL Provides fast communicating, is stable and reliable Offers better compatibility This is an USB to RS232 / RS485 / TTL Industrial Isolated Converter. It...




www.robotshop.com


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