Sending specific commands over modbus

[CDC1]

I am connected to an STS pressure sensor (DTM.OCS.S) which uses two-wire Modbus RTU connected to a RS485/USB converter.  Playing with the toolkit I can at least get a response from my sensor though it seems gibberish.  Using my default unit address of  240 at memory address 40021 (supplier (STS) spec sheet  says this is where unit address is stored so I expect to get 240 (F0) back), using the MBV_lecNBitsSortie(1).vi, all the bits are off.  I added in indicator to the Information Out output and the send and received frames are gibberish, exception code is 2.  

What I need is to send specific commands to device (such as F0040000000264EA which is based on the following construct: UnitAddress(B)FunctionCode(B)StartIndex(2B)Length(2B)crc(2B) to my device and read the response. 

Any help anyone could offer would be great. 

Chris

[Olivier-JOURDAN]

Hello Chris,

Don't have LV2018 currently available on my computer, anyway could you use the tool provided in LabVIEW menu (Tools >> SAPHIR >> GModBus over TCP >> Client Simulator to try different requests quickly and without coding. Note that the tool uses the VIs you can find in the palette.

Could share screenshot of the tool with the settings that not working?

Thanks,

Olivier