MYPRO cpIII communication problem

[Karsu]

compressors are Mayekewa screw type with Mypro cp3

In a scenario
Compressors will work in Auto-stage
and it is required to monitor compressors in a special SCADA software, just to monitor

Among with various data related to sytem, it is intended to collect the data of compressors to a device(basically a PLC) which communicates with RS485. The connection with pc will be formed over this device.

Problem:
a collegue insists the RS485 protocols are being used by CP3 and this device are "different"!
Also I have encountered a similiar topic which mentions Mypro CP3 and PLC connection is not feasible though imho the answers were a bit not complete(thus i brought this topic).

and the information related to CP3 on internet is very very limited.

Any ideas or information? Or can you at least tell me why i can not take input from CP3 to PLC (recall: both use RS485)

or any different ideas for monitoring?

Thank you for help

[persim]

Hi
No problem to communicate with a CP III have done this already in 2001, latest project when I worked
with communication to 5 CP III at ones function fine. I'm using a SAIA Burgess PCD3.M5340 and using
the RS485 port. The communication with the CP III is thoug based on ASCII character transmttion.

Example:
To read values from a CPIII you need to send the following string:
STX,_,A1,A2,'04RDDT',_,_,ETX

STX start of text ASCII 2
_ space (blank)
A1A2 Adress of CP II 1..31) if it is 1 A1=0 A2=1
04RDDT fixed ASCII characters
ETX End of text ASCII 3

The returning result is a text string consisting of 276 characters which you the have to split up

Best regards

If you would leave your mail adress I could give you the doc..

[hoanglonghui]

hi all
i use the PLC s7 300 to communication with mypro cp3 .I read manual CPIII so i use the format:
STX,SPX,A1,A2,0,4,R,D,D,T,_,_,SPC,SPC,SPC,ETX
it is correctly ?