West Control Solutions N8080 (for 2xxx) - Manual (Page 23)

NOTE: This option and the Serial Communications option are
mutually exclusive.
1.3.5 Relay Outputs
Relay 1 is a standard feature; it is tied to Alarm 1. Relay 2 is an option; when fitted,
it is tied to Alarm 2. The contacts are rated at 2A resistive @ 120/240V AC.
1.3.6 Linear Output
This option provides a 10-bit linear output signal representing the process
variable. The range of this output is selectable in Configuration Mode (see
Subsection 3.4).
1.3.7 Serial Communications Option
The cable used should be suitable for data transfer at the selected rate (1200,
2400, 4800 or 9600 Baud) over the required distance. Transmitters/receivers
conform to the recommendations in the EIA Standard RS485.
The “A” terminal on the Indicator (Terminal 17) should be connected to the “A”
terminal on the master device; the “B” terminal on the Indicator (Terminal 16)
should be connected to the “B” terminal on the master device; the “Common”
terminal on the Indicator (Terminal 18) should be connected to the “Common”
terminal on the master device.
Where several Indicators are connected to one master port, the master port
transceiver in the active state should be capable of driving a load of 120k
Ω per
Indicator; the master port transceiver in the passive state must have
pull-up/pull-down resistors of sufficiently low impedance to ensure that it remains in
the quiescent state whilst supplying up to
± 100 µ A each to the Indicator
transceivers in the high impedance state.
NOTE This option and the Digital Input option are mutually exclusive.
PM091-1 Volume II 1-5
59136