curiocity

Q1: A stream of bytes need to be exchanged between the "RTUCI task" and the "Ebilock 850" (end device). So, when a typical byte stream say, 0x67, 0x89s received by the RTU from RTUCI task, will it transmit 0x67 and 0x89 to "Ebilock 850" through CP341 (RS-232 cards), OR will it transmit 0x36, 0x37, 0x38, 0x39 (where 0x36 is ASCII code for 6, 0x37 is ASCII code for 7, and so on), in case ASCII protocol is selected for CP341?

Kaulquappe

Yes, select ASCII protocol.

curiocity

Q2: We are required to use Modbus TCP/IP between "RTUCI task" and RTU. Can we do this, where we are required to use ASCII between RTU and "Ebilock 850"?

Kaulquappe

You can use the ethernet interface of the PN CPU for ModbusTCP communication. I recommend to use the Modbus library 2XV9 450-1MB02.

curiocity

Q3: As seen in the block diagram, there are two kinds of end devices connected to the RTU ("Ebilock 850" and "Relat Interlocking"). The RTUCI task has two different station objects called "Ebilock Station" and "RI Station" that can independently take care of the what messages they need to exchange with RTU, with regard to those two end devices. The plan is to use two TCP connections with RTU (one for communicating messages related to "Ebilock 850", and the other communicating messages related to "Relay Interlocking").The two TCP connections would use same IP address, but different ports on the RTU. So, the question is: Can the RTU application be written to support this use case, in particular, communicating with RTUCI over two TCP connections?

Kaulquappe

The above mentioned ModbusTCP library is capable of using different port numbers for the communication. So it is possible touse two TCPconnections. In this case you need two calls of the Modbus block with different connection IDs and instance DBs.

curiocity

Q4: If the usecase mentioned in Q3 is possible, can we use ports 502 and 3050 to distinguish the two TCP connections?

Kaulquappe

yes