Wood and Douglas 1335, Operating Instructions Manual

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1892 1335 - Orion Radio Modem Operating Instructions - v2.9 / Aug 2009
Mode E Parameters
Unit ID (ATS170) The Base must have the UnitID 0 and is connected to the SCADA.
The SCADA must insert UnitID 0 as the source in its messages so
that replies are correctly routed on return.
Outstations should be given Unit IDs from 1 up to 254, although they
need not be contiguous.
Dest ID
(Destination for
messages which
the unit
initiates )
(ATS171)
During normal polling, this setting is ignored: the destination of
messages from the Base is dynamically inserted by the SCADA and
Outstation replies always go back to the sender.
If alarms are used, Outstations must be set to DestID = 0 to contact
the Base.
User Data transmissions are sent to the DestID specified at the unit
of origin. This may be 255 to broadcast if required.
Group ID
(ATS169)
Any number between 1 and 254, all units the same within the Group.
Unlike the UnitID and DestID, the GroupID is added to messages by
the Base unit, not the SCADA, and checked by the receiving unit.
Poll Timer time
(Outstations only)
(ATS183)
Outstations check for a poll during the set period plus 3s. If a poll
does not arrive during the period, an alarm is raised, so it should be
set for the longest poll period expected. Poll period can be from
100ms up to 182 hours (just over a week). Set to 0 for no check. (In
mode E, a Poll Timer time of zero does not cause spontaneous
reporting behaviour as it does in Mode I.) This parameter is ignored
at the Base.
Permit initiation of
transmissions
(ATS330)
(Outstations only)
All alarm messages can be suppressed by turning this setting to off.
The Alert still functions if selected. However, replies and
acknowledgements in
response to a message from another unit are
still made. User Data transmissions are unaffected.
Master Failsafe
control
(ATS188)
(Outstations only)
If communications are lost and a Comms Alarm is raised, outputs
are made to take on values you specify. If this setting is turned to off,
this no longer happens and outputs remain as they are.
No. of missing
messages before
Comms Alarm
(ATS184)
(Outstations only)
If an Outstation does not hear a poll for this number of poll periods
(plus 3s for each period), or receives no acknowledgement to this
number of spontaneous or alarm transmissions, a Comms Alarm is
raised. The Poll Timer
(ATS183) sets the poll period.
Number of
transmission
attempts
(ATS185)
(Outstations only)
If acknowledgement is not received when expected after a
transmission, repeat attempts are made until an acknowledgement
is received or a total of this number of transmissions have been
made.
Note: Some parameters do not apply to the Base in this mode, because it has no input/output,
and it is the external controller which is responsible for polling, acknowledgement,
retransmission etc..