Siemens SIMATIC CP 340 - 20 Ma-TTY Interface on the CP 340-20 Ma-TTY

Product Description
1.4 Properties of the serial interface
PtP coupling and configuration of CP 340
20 Manual, 04/2011, A5E00369892-03
1.4.2 20mA–TTY interface on the CP 340–20mA-TTY
Definition
The 20mA-TTY interface is a current-loop interface used for serial data transmission.
Features
The 20mA-TTY interface has the following features and meets the following requirements:
Type: Current-loop interface
Front connector: 9-pin sub D socket with screw-locking
20mA TTY signals Two isolated 20 mA current sources, receiving loop (RX) "–" and "+" send
loop (TX) "–" and "+"; all isolated from the S7-internal power supply
Max. baud rate: Baud rate: 9.6 kbps
Max. cable length: 100 m active, 1000 m passive;
Cable type LIYCY 7 x 0.14
Standard: DIN 66258 Part 1
Degree of protection: IP 00