R911299722 / 02 | Rexroth IndraControl VCP 20
Interfaces
7.1.1
TTY / 20 mA Current Loop (X3-SER1)
7.1.1.1 Pin Assignment
Electric Drives and Controls | Bosch Rexroth AG
Depending on the wiring, it is possible to connect the interface either as
an active or passive current loop. The transmit line and the receive line
are each provided with a separate 20 mA power source. The compli-
ance voltage is approx. 24 VDC.
The 20 mA power should be supplied by the transmitter unit. This
decreases crosstalk on the signal lines considerably.
In idle state (signal logic 1), a 20 mA current loop can be measured in
the cable.
Signal Logic 1
Current Flow 20 mA
Signal Logic 0
Current Flow Interrupted
Fig. 7-3: 25 pin D-SUB female connector strip
Connector in the small operator terminal: 25-pin D-SUB female con-
nector strip
Pin Designation Function
10
T+
Transmitted Data, Positive Polarity
13
R+
Received Data, Positive Polarity
14
R-
Received Data, Negative Polarity
19
T-
Transmitted Data, Negative Polarity
Fig. 7-4: Pin assignment TTY / 20 mA, passive
7-3