W&T 58031, Руководство пользователя

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58
W&T
Interfaces and displays
5.4 Option: 20mA interface
All Com-Servers in the Highspeed series with the exception of
model 58633 can be equipped optionally with 20mA interfaces
instead of the RS232/422/485 combi-module.
The interface can be used as an active or passive 20mA
component. In the active mode the interface supplies the
current required by the respective 20mA loop, while in the pas-
sive mode the loop current must be supplied by the connected
device.
Pin assignment and function 20mA, DB9
Pin
1
2
3
4
5
6
7
8
9
Signal
Data Out 20mA
Data Out +
Data Out -
Data Out GND
n.c.
Data In 20mA
Data In +
Data In -
Data In GND
Function
Current Out +20mA
Output
Output
Current Out Ground
--
Current In +20mA
Input
Input
Current In Ground
The operating mode can be selected for both loops seperately.
Examples of interface switching into active/ passive mode are
shown on the following drawings: