INSTALLATION |
67
PDM
PDM Operator's Manual Version 2.4a • September 2019
Serial Port
RS-232
The RS-232 pins are configured as a computer DTE port, similar to the Comm 1 jack on
desktop computers.
If you want to control it from a computer or dumb terminal, you’ll need a DB-25 null mo-
dem or a cable that reverses pins 2 and 3 (data), pins 4 and 5 (flow control). Since PDM uses
standard pin configurations, you should be able to use an easily available DB-25 to DB-9
adapter to connect more common 9 pin cables.
RS-232 can be used either for control, or to delay data. In the case of delays, data gets sent
on the same RS-232 connector as it’s received, so if you have one device generating data and
another one listening, you’ll need a
Y
cable to split the TX and RX signals.
RS-485
There are also two independent RS-485 differential data lines on this connector. Each is
independently controlled and programmable as input, output, or bi-directional.
Serial Pinouts on DB-25
PIN
SIGNAL
1
NC
2
RS-232 TX
Output from PDM
3
RS-232 RX
Input to PDM
4
RS-232 RTS
Do not use
5
RS-232 CTS
Do not use
6
No Internal Connection
7
Ground
8
RS-485 Port 1 +
Differential pair. Bi-directional.
9
RS-485 Port 1 –
10
No Internal Connection
11
RS-485 Port 2 +
Differential pair. Bi-directional.
12
RS-485 Port 2 –
13 - 25 No Internal Connection
NC — No internal connection
Differential pair. Bi-directional.
Differential pair. Bi-directional.
Содержание PDM
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