315-4PN33

n In opposite to ASCII and STX/ETX, the protocols 3964R, USS and
Modbus require the acknowledgement of the partner.
n An additional call of the FC/SFC 217 SER_SND causes a return
value in RetVal that includes among others recent information
about the acknowledgement of the partner.
n Further on for USS and Modbus after a SER_SND the acknowl-
edgement telegram must be evaluated by a call of the FC/SFC
218 SER_RCV.
6.3 Deployment of RS485 interface for PtP
n Logical states represented by voltage differences between the two
cores of a twisted pair cable
n Serial bus connection in two-wire technology using half duplex
mode
n Data communications up to a max. distance of 500m
n Data communication rate up to 115.2kbaud
9pin SubD jack
Pin RS485
1 Shield
2 M24V
3 RxD/TxD-P (Line B)
4 RTS
5 M5V
6 P5V
7 P24V
Properties RS485
PtP interface X3
VIPA System 300SDeployment PtP communication
Deployment of RS485 interface for PtP
HB140 | CPU | 315-4PN33 | GB | 14-43 84