Author Topic: modbus address  (Read 4880 times)

Jane

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modbus address
« on: November 02, 2011, 09:12:23 PM »
hi....

To read register '4097' , and assuming that the device has ID = 01 .
then what  the modbus tcp/ip command at a F1616 ladder?


READMODBUS (1,1, XXXXX) ???


one more... to read register '300019'and assuming that the device has ID = 01 .
then what  the modbus tcp/ip command at a F1616 ladder?


READMODBUS (1,1, XXXXX) ???
« Last Edit: November 02, 2011, 09:13:26 PM by Jane »

support

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Re:modbus address
« Reply #1 on: November 03, 2011, 09:17:28 AM »
Is "4097" a Modbus register address? Usually Modbus register addresses are something like 1xxxx, 2xxxx,3xxxx,4xxxx

READMODBUS and READMB2 can only handle 3xxxx and 4xxxx. The default is to use Modbus function 03 to read the Holding Register address at 4xxxxx.

If you run the SETSYSTEM 6,4 then you can change it to use the function 04 to read the 3xxxx modbus "Input Register" space.

All other addresses can only be handled using TBASIC program that involves the functions INCOMM, OUTCOMM and CRC16.  Please refer to:

http://www.tri-plc.com/yabbse/index.php?board=2;action=display;threadid=298
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