Siemens S5-135U/155U appendix Data Transmission Rate Pin Assignments TTY Submodule

CPUs, Memory Cards, Memory Submodules, Interface Submodules

Data Transmission Rate

Pin Assignments

of the TTY

Submodule

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:

13

25

14

1

²: Input ³ : Output

Pin	Designa-
	tion
1	Shield

924 V external

10+ TxD

12+ 20 mA

13+ RxD

14± RxD

16+ 20 mA

19± TxD

21± 20 mA

24± 20 mA

Current direction

²

³

²

³

³

³

²

²

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	5-107
C79000-G8576-C199-06