Pakscan IIE System Manual
124 of 132
Publication S177E V2.0 Issue 03/05
16.5 External Connections
The following information applies to the connectors that are on the rear panel of the 19-inch rack.
16.5.1 Loop Connections and Digital I/O
Loop Connections and digital I/O are brought to
terminal blocks and to a 25-way D-Type
connector. There are two sets of terminals and
connectors to support two master stations in the
rack. If only one master station is fitted, or if the
system is a "hot standby" type then the "master
station A" terminal block or 25-way D-type must
be used.
Notes:
1. ESD Input: The ESD input terminals should
be linked for normal operation and
disconnected to cause Emergency
Shutdown, (providing that ESD is enabled).
2. Master station Main/Backup Inputs: In dual
redundant systems, these inputs define
which master station defaults to being the
main unit, and which to being the standby
unit.
Link Fitted
- Standby
Link Not Fitted
- Main
3. Terminals 18 to 21 are only used as
described on the 'A' side
4. The alarm contacts shown, (terminals 1 to
9), are shown in the “powered off” state
5. Terminals 1 to 3 show the alarm contact
state with a master station alarm. Terminals
4 to 9 show the alarm contact state with no
field unit fault.
6. When using a hot standby master station
both terminal blocks may be used, but only
the NO contact will give a true indication of
the alarm state.
Terminal
Number &
25 way D-
Type pin
Function
1
Alarm relay COM
2
Alarm relay NO
3
Alarm relay NC
4
New FCU alarm relay COM
5
New FCU alarm relay NO
6
New FCU alarm relay NC
7
FCU alarm relay COM
8
FCU alarm relay NO
9
FCU alarm relay NC
10 ESD
input
11
ESD input common
12
Loop port A OUT
13
Loop port A IN
14
Loop port A screen
15
Loop port B OUT
16
Loop port B IN
17
Loop port B screen
18
Master station “A” main / backup
19
Master station “A” common
20
Master station “B” main / backup
21
Master station “B” common
22
) Link 22 and 23 together if PS300
23
) switch module is not fitted
24
) Link 24 and 25 together if PS300
25
) switch module is not fitted
Fig 43: External Connections to Terminals
