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1. Are you on the right virtual COM port for the USB/485 converter? Check Windows' Device Manager > Ports and select the right COM port in Modscan's Comm setup. 2. What is a PNU? are you sure 38 is hexadecimal?

the generalities of ChatGPT . . .

Can you provide one concrete example of how it's used and the business result?

Back when I started dabbling in this in the 1990's, the spec was a maximum of 32 "loads' on a 485 bus, as defined by the chip manufacturers and the EIA-485 standard. Wikipedia says that EIA-485 got revised and renamed to TIS-485 in 1998 and the maximum number was not defined by the standard...

Pages 2-4 (pdf) of publicly available first chapter of the ISA publication, Calibration Principles, gives a broad overview of instrumentation calibration tolerances. https://www.isa.org/getmedia/a9356c34-5956-4952-9888-d6df8dd3e7ba/calabration-principles-chapter1.pdf

I'm not clear on why you call it a 'timer'. The PLC does the on/off timing, does not it not? Don't you need a solid state relay (SSR) that will switch a 12Vdc 1/2A load at 10Hz, right? Here's an Amazon SSR and the heat sink (separate) looks like it can mount on a DIN rail...

The 'original' flow meter flows less volume at the DP across the flow meters' parallel path than the magmeter. Flow through flow meters in series has to be the same volume through both flow meters. Flow through flow meters in parallel shows the relative volumetric flow of each path.

Have you tried the search function? Unfortunately, CSA has retired and moved onto greener pastures. His last post is here: https://control.com/forums/threads/mark-counter-and-timer.50432/ But there are some others who might well answer your question.

Timeout means that the Master fails to gets a reply from the slave. Some reasons for that are 1. Cheap USB-RS-485 converters are known to fail with the tight timing restrictions of Modbus RTU. Those with FTDI chipsets have proven reliable. The checksum error makes me suspicious of the...

Assuming that the field devices have a typical spec, like 12-32Vdc for power, then yes, you can power field transmitter(s) with a set of three 9V batteries (27Vdc) in series. I have used a set like that for powering field transmitters when there were power supply issues. I used a plug/jack...

By the Modbus standard, no, because packet collisions result in poor or no communications. With a separate bus arbitrator module between the Masters and the slave bus, Yes. See these earlier discussions on the same topic...

The answer depends on what you mean by "zero trim". If "zero trim" means a minor adjustment generally due to the installation orientation of the DP transmitter, then yes, any major player, industrial grade PT will have a HART or keypad instruction to trim a minor offset to zero, assuming that...

we would like the user to just enter the list of offset´s and slave id´s so we could read the devices and and then convert automatically. Good News! You're in good company. You and everyone else in the world would love to simplify data communications to that exent. Bad News! No way to do...

1. Generic TCP/RS-485 converters do a poor job, if any, for Modbus because of Modbus RTU's timing requirements. Converters that work for Modbus TCP?RS-485 are specifically designed for such and sold for Modbus service. I couldn't find a TS-1200 converter in web search so you need to confirm...

ChatGPT ?

1. I think you are reading the wrong register for the Device Id. When Modscan displays its target slave address register value, the register value is a one-based decimal value (it can be changed to display in hex, but when that is done, the word 'hex' appears so you know that the register...

No, I can't help on ABB's, but I do know that those tapered rectangularish Siemens electronic flow transmitters with the sloped indicator will die if removed from its wiring junction box (which it sits on top of) when it is powered and running. It says so in the manual. I had to buy a...

What's to align? There could some parallax in the photos, but from the photos it appears that the instrument is within 0.5% from zero to span. The manufacturer should have a calibration/alignment procedure.

According to the tables on this engineering site, 1000 feet of altitude or elevation above sea level is not exactly 1.00 inches of Hg. https://www.engineeringtoolbox.com/barometers-elevation-compensation-d_1812.html I would think that a certified mercury barometer would a suitable tool for...

Peter, 1. The product deserving of "Dummy mode" (returning X number of registers regardless of the requested number) deserves to be named publicly for induction to the Modbus Hall of Shame. That level of deviancy from the Modbus spec should not go unrewarded. 2. On the topic of...