Westermo LD-34 - Manual (Page 2)

8 6603-2001
Description LD-34
General
The LD-34 is a 4 channel RS-232 switch. The unit has one input channel that com-
municates with a selected output channel. A sixth channel called the “Expansion channel”
is provided for onward connection to a modem or another unit. All channels are DCE
connections. RTS, CTS is available on all channels flow control.
Channel selection is made by external signals on the “Digital in” connector or by
raising the RTS signal line.
The front cover has 9 LED's to indicate the state of the various communications paths.
As with all Westermo products the LD-34 provides a high level of galvanic isolation
on the power supply side through transformers and through optocouplers on the inputs.
Channel one and the digital inputs are isolated from channel 2-6.
All operating parameters are set-up via DIP switches located under the lid on the top
of the unit.
The LD-34 is available in both AC (230V) and DC (12-36V) supply voltage.
Digital In
The Digital Inputs, A0,A1,EN, E1 and COM can be used to select the required output
channel. The inputs have a voltage range of 10-30 VDC between A0, A1, EN, E1 and
COM, COM is equivalent to 0V (–). It is possible to reverse the polarity, which means
COM = 10-30 VDC and the inputs are activated by 0V(-) being applied.
The maximum input voltage on the inputs is 30 VDC at a maximum current of
5mA per input. Switching time when channel is less then 0.1 ms.
All digital inputs are galvanic isolated via optocouplers.
RTS control
Raising the RTS signal on channels 2-5 activates this channel. Only one channel can be
activated at a time. If two RTS lines have active, the first gets priority.