modbus rtu whit siemens s7-318

hi

I have a profibus gateway connected to my plc s7 318

http://www.hardwarept.co.uk/product...nectivity/3/data-gateways/22/drl-dps-srm/187/

and I would like to know what kind of function block do I need to comunicate via modbus rtu I can not finde any information about what program block do I need.

this plc bill be the master in the modbus network

some3 said:

hi

I have a profibus gateway connected to my plc s7 318

http://www.hardwarept.co.uk/product...nectivity/3/data-gateways/22/drl-dps-srm/187/

and I would like to know what kind of function block do I need to comunicate via modbus rtu I can not finde any information about what program block do I need.

this plc bill be the master in the modbus network

Click to expand...

Hello;
Sorry, but the S7 will be a master on Profibus-DP.
The gateway will act as a Modbus Master.
The only thing that a DP master will see is the DP-slave interface of the gateway, and as such, you can access the data from the DP-slave directly on PIWxxx and PQWxxx addresses, or using SFC 14 and SFC 15 when you want to write or read a block of data to/from the slave.
The gateway configurator will establish the link between the Profibus data of the DP slave and the Modbus addresses that the Modbus master will exchange with the Modbus slaves.
Hope this helps,
Daniel Chartier