West Control Solutions N8080 (for 1xxx) - Manual (Page 22)

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.
1-6 Volume II PM090-1
59135