Pin Assignments Of The - Siemens S5-155U System Manual

Interface Submodule
Data transmission rate

Pin assignments of the

TTY submodule
13
25
14
1
5 - 80
The TTY submodule feeds in the current (20 mA) via jumpers in the
connector of the standard connecting cable. The 24 V required for
generation of loop current is taken from the power supply of the PLC.
In the quiescent state, with a correct loop current connection, there
should be a flow of 20 mA (= logic 1). When the current is interrupted
there is a logic 0.
The following applies to the TTY signals:
Logic 0 is represented by: no current
Logic 1 is represented by: current (20 mA)
A maximum of 9600 bps is permissible for data transmission with the
TTY submodule.
Shown in the figure are the pin assignments of the 25-pin
subminiature D-type connector in the front plate of the TTY
submodule:
Pin Designa- Current
tion direction
1 Shield
9 24 V
external
←
10 + TxD
+ 20 mA →
12
←
13 + RxD
→
14 - RxD
+ 20 mA →
16
→
19 - TxD
←
21 - 20 mA
←
24 - 20 mA
← : Input
→ : Output
Remarks
This connection is changed over
between 24 V internal and 24 V
external with jumper J3 (see next page).
Current source, transmitter
Current source, receiver
Current return
Current return
System Manual
C79000-B8576-C199-03