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7
Installation
Page 112
gas-lab
Q1
7.2.2.3
Serial process board MSER2
The MSER2 serial process board provides two interfaces that support V24
(RS232) as well as RS422 and RS485. The table below shows the assignment
of the individual PINs:
Signal
Assignment
TXD
RS232: Transmitted data
RXD
RS232: Received data
RXB
RS422/RS485: Received data (B)
RXA
RS422/RS485: Received data (A)
TXB
RS422/RS485: Transmitted data (B)
TXA
RS422/RS485: Transmitted data (A)
SGD
Signal ground
SH
Shield
In the
gas-lab
Q1 the MSER2 board serves as protocol gateway functionality for
the connection of a host computer.
Notes:
When RS422 and RS485 are used, a matching resistor of 120 ohms may
be required in the receiver between RXB and RXA, depending on the cable
length.
In case of RS485, you have to externally connect RXB to TXB and RXA to
TXA.
Pay attention to the specification of the individual protocols. For instance,
there are protocols that render a connection via RS485 impossible (e.g. in
case of RK512).