Basic Documentation

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Siemens Universal controllers RMU710B, RMU720B, RMU730B CE1P3150en
Building Technologies Aggregates 03.10.2011
10.1.10 Precommand checkback signal
A precommand checkback signal can be configured for each fan block in addition
to the precommand. The precommand checkback signal provides information on
whether or not the precommand was implemented (e.g. via damper end position
switch). Only then is the fan switched on.
Main menu > Commissioning > Extra configuration > Aggregates > Supply air fan >
Main menu > Commissioning > Extra configuration > Aggregates > Extract air fan >
Operating line Range
Precommand checkback
signal
---, N.X1, N.X2, ... (digital inputs only)
If there is no Precommand checkback signal during the set Precommand runup
time, a fault message appears and the fan is not started. Precommand "Off" is
given after the Precommand rundown time.
If the Precommand checkback signal drops off during fan operation, the fan is
switched off immediately and precommand "Off" is issued after the Precommand
rundown time. A fault message appears. The fault message is removed only after
acknowledgement and reset.
Using the Precommand checkback signal is sensible only if combined with the
configured precommand.
PcmdRnup
PcmdRnup
PcmdRndw
PcmdRnupPcmdRndw
PcmdRndw
0
I
0
I
Off
Fan
Start-
condition
On
Precommand
Fan fault
Precommand
checkback
Off
On
Off
On
Off
On
3150D09en
Normal operation Precommand
checkback signal
missing
Precommand
checkback signal
lost during operation
Fault message
acknowledged
+ reset
PcmdRnup = Precommand runup time
PcmdRndw = Precommand rundown time
No. Text Effect
1114 Supp air precom no
checkb sign
Urgent message; must be acknowledged and
reset
1124 Extr air precom no
checkb sign
Urgent message; must be acknowledged and
reset
Configuration
Note
Function diagram
Key
Fault status messages