Thermcraft XST-2-0-12-1V1-E29 Instruction Manual page 211

Installation and Operation Handbook
5.2 Programmer States
Programs has five states:− Reset, Run, Hold, Holdback and End.
State Description
In Reset, the programmer is inactive and the controller behaves as a standard
Reset
controller, with the setpoint determined by the value set in the lower readout.
In Run, the programmer varies the setpoint according to the active program.
Run
Hold In Hold, the program is frozen at its current point. In this state you can make
temporary changes to any program parameter (for example, a target setpoint, a dwell
time, or the time remaining in the current segment). Such changes only remain
effective until the program is reset and run again, when they are overwritten by
the stored program values.
Note: When a program is running, you cannot alter a cALLed program until it
becomes active within that program.
Holdback indicates that the measured value is deviating from the setpoint by more
Holdback
than a pre-set amount and that the program is in Hold, waiting for the process to catch
up. See Holdback in the section on Automatic behaviour later this Chapter.
A master controller can re-transmit a setpoint value to a number of slave units using
PDSIO setpoint retransmission. Any of the slave units can generate a holdback
signal which will also flash the HOLD light. Holdback will also occur if the PDSIO
output is open circuit. This can be disabled in configuration by selecting the PdS
output as SP.nH - 'setpoint retransmission without holdback'
The program is complete.
End
HA025041 issue 12 Aug 14
Table 5-2: Program states
Programmer Operation
Indication
Both the RUN and
HOLD lights will be
off
RUN light on
HOLD light on
HOLD light flashes
HOLD light flashes
RUN light flashes
5-3