Hello everyone,

I am attempting to create a S7 program in TIA v18 that tests communication between two CPUs using CM PtP modules. I have a S7-1500 CPU and a ET200SP CPU with a CM PtP RS422/485 HF and CM PtP ST and using four-wire mode (full-duplex).

I am using the 3964 protocol and have looked into the procedure to get the two devices communicating: Configure the CMs in either the device configuration or dynamically using Port_Config and P3964_Config. Once they are configured, the instructions Send_P2P and Receive_P2P are used to send a data buffer between the communication module and communication partner.

Currently, I've tried configuring the CMs both ways and the devices get configured (Port_Config and P3964_Config DONE status goes to TRUE), but I'm having trouble with the Send and Receive. The send function has the error code 8386, which says to "check the interface cable, transmission parameters, and whether the receive function has been configured correctly at the partner device." Where there are two CPUs I have two devices in the TIA project, so i have two different programs running at the same time. The Send_P2P is on the S7-1500 using the RS422 CM and the Receive_P2P is on the ET200SP CPU (1512SP-1 PN). The done flag of both stays at 7002 all the time and nothing is sent; the status of Send_P2P and Receive_P2P stay false. The TX on the RS422/485 flashes but there is no RX flash on the ET200SP's CM.

I have attached a photo of the Send and Receive P2P functions. Has anyone had trouble with this before? Thanks

Hello AutoGen_4812619,

If you want to attach more than one file, you can create a zip file. 

Best regards,
Jen_Moderator