AC800M_MODBUS RTU_MB READ_Start Adress issue
Hi I am trying to communicate to PM856 via COM3 to the Modbus Buss Slave software.
I want to read 30001 to 30009 integers address from thorough this. My laptop which having Modbus slave software is connected to PM856 at com3 by using USB to serial converter.
At control builder I am using MBconnect and MBread. And I am giving STARTADDRES of MB read is %IW10#0001.But still there is not communication. Please advice. Advance thanks
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Hi
Some queries :
- What Baud Rate you have selected.
- Cable Pin Connections In AC800M controller(RJ45 plug) should be pin no 3-Tx; 6-Rx; 4&5-GND.
- Have you tried by keeping Poll Time= 0
Best Regards
Sunny Khatri
Answers
Hello,
If you are using function code 4 (reading input register) then the address will be 30001-39999 then the address in the AC800M side should be %IW10#000=30001. and not %IW10#0001=30002
along with this please look into the modbus parameter of both the sides, You can chekc the error code easily using CBM online help by pressing F1
by Govindaraj
can you specify the error code of Modbus blocks?
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