Hi,

I have one question. I have a Modbus slave which supports and uses the function code 43. I know, that it is not normally supported by the SPS. My question is, if it is possible to send raw Modbus frames, where ich can use function code 43. For example that only the CRC is calculated and the pure data is supplied by myself?

Thanx

Hello,

basically if you know frame syntax (send/receive), I don't see problems implement.

Nantec

Hi,

I have one question. I have a Modbus slave which supports and uses the function code 43. I know, that it is not normally supported by the SPS. My question is, if it is possible to send raw Modbus frames, where ich can use function code 43. For example that only the CRC is calculated and the pure data is supplied by myself?

Thanx

What you ask is not easy to do.. even if possible. How many slaves?

Some devices provide for mapping functionality to a memory area. Could this help you?

Hi,

Thank you for the fast answers. It helped me, because now I know that it is possible. It is only not nice, that the CRC16 must be written by oneself.

By our device, the configuration is made with the function code 43 in CANopen style and then there is a mapping to the normal MODBUS memory area with access via the supported function codes.

Greetings

Hi,

our slave is originally a CANopen slave. For parametrization, we implemented the function code 43 (encapsulation....CANopen) which was designed for gateways, but we use it as a way to communicate with the slave. The problem is that some SPS and Master are not so flexible to use this function code.

Greetings,

Nantec

Hi,

our slave is originally a CANopen slave. For parametrization, we implemented the function code 43 (encapsulation....CANopen) which was designed for gateways, but we use it as a way to communicate with the slave. The problem is that some SPS and Master are not so flexible to use this function code.

Greetings,

..what if you could make the PLC to be CAN capable?

William_B

Nantec

Hi,

our slave is originally a CANopen slave. For parametrization, we implemented the function code 43 (encapsulation....CANopen) which was designed for gateways, but we use it as a way to communicate with the slave. The problem is that some SPS and Master are not so flexible to use this function code.

Greetings,

..what if you could make the PLC to be CAN capable?

 That would be the best :) but for Modbus only networks they must use our PC Master tool, configure a image with the parameter they need and then they can use the normal function codes with their SPS on that image.