Dear Saud,

I had downloaded the sample project you posted, USS.zip. But due to lack of experiences of related background knowledges so I am still suffering to leran this sample. Does any additional documentationavailable or comments from your side to help me. Meanwhile, I am alsolooking for MODBUSdrivers both on Master and Slave mode. Could you send me for it. Thanks so much in advance for your great helps.


With Best regards,
Afefe

Modbus Slave Program for 300 ptp CPUs.

Hello Vithani;

In the MM440, the parameter for USS node address is P 2011, and its value must be 0-31.

See this Tips and Tricks project diocumentation for the S7-200 USS protocol with a MM420:

2,5 Parameters for the MM420

...

//P0700=5 Set local/remote control mode by setting

//P1000=5 Set local/remote control mode by setting

//P2010 Index 0 Value 7 (19200) Baud rate

//P2011 Index 0 Address 1 (0 to 31) Slave address

//P1120= 0.00 (0 to 650.00) Acceleration ramp

//P1121= 0.00 (0.00 to 650.00) Deceleration ramp

//

// Set the serial link timeout by setting:

//P2014 Index 0 Value 300 (0 to 65535 ms)

// Value 0 is without monitoring

// When you change this value, the PLC must already carry out the

// USS protocol, as otherwise Error 72 is immediately reported.

// You must also change the value with the arrow pointing down,

// as the first value would be 1 ms if the arrow were pointing up, resulting

// in the immediate reporting of an error.

,,,

Attached you will find a pdf version of the complete Tip documentation.

Hope this helps,

Daniel Chartier

Hello again Vithani;

Maybe this document provided by Late in an old thread, could help you out with the details of the USS protocol:

point to point CP340 RS485 communication with MicroMaster MM25/2

Hope this helps,

Daniel Chartier