A question on modbus

[Amber via Tech-talk <tech-talk at aps.anl.gov>]

Hello everyone，

I am using a device with Modbus-RTU protocol. The communication data is transmitted in hexadecimal words.

I want to use the modbus module in epics to solve this problelm. 

When reading device data, the follwing sentence is used in the .cmd file:

drvModbusAsynConfigure("V1","Power", 1,3,0,1,0,1000, "Power")

and in the substitution file:

file "../../db/ai.template" { pattern

{P,         R,      PORT,               OFFSET, BITS,  EGUL,  EGUF,   PREC,   SCAN}

{power:,    V_read,   V1,   0,      16,    0.,   655.35,     2,      "I/O Intr"}

}

There is another command to open the device, which should write " \x01 \x05 \x00 \x00 \xFF \x00  \x8C \x3A" to the device.

Command	01	05	00	00	FF	00	8C	3A
	Address	Function code	Register address 0		Data 0		CRC
Reply	Be same with command

After reading all the examples I still don't know how to send this command with modbus module correctly. I think I didn't understand them clearly.

Would you like to give me some advice?  Is it suitable to use modbus module?  How to realize it?

Thank you very much.

with my best wishes,

Kevin