22
Changing the Behavior of the Auto Select Channel Mode
The default values for these commands have been carefully chosen to work well under most applications.
LDxxx
sets auto crossover delay, where
xxx
is in msec (default = 100).
RD
reports LD value.
LHCxxx
sets high channel crossover point, where
xxx
is percentage of Hi channel (default = 0.9).
RHC
reports LHC value.
LLCxxx
sets low channel crossover point, where
xxx
is percentage of Low (default = 100).
RLC
reports LLC value.
The active channel is reported in parameter
“w”
in the Operational Status Word (see Table 9, page 37).
Set Safe State for Error Mode
If the controller encounters an error, it applies the Safe State to the valve. The Safe State is set at the factory
to Valve Open. The messages described here change and report the Safe State.
Note
If the Safe State value is not set, it defaults to the
open position
.
To change this default, enter one of these commands:
SS0
= Open valve
SS1
= Close valve
SS2
= Hold valve position
SS3
= Activate Safe value
(applicable to DeviceNet platforms only)
SS4
= Cycle the valve
(factory only setting)
Note
The unit switches to the selected safe state for any of these error conditions:
When in Lock Hi or Lock Lo range and the Baratron is disconnected for the selected channel.
When in auto range and either Baratron is disconnected.
To report the Safe State, enter:
RSS
The controller responds with the message
SS
value
, where:
SS0
= Open valve
SS1
= Close valve
SS2
= Hold valve position
SS4
= Cycle the valve
Valve Control
N0
= Normal valve action (default, typical in downstream pressure control applications)
N1
= Reverse valve action
A valve can be controlled to open and close in a normal or reverse direction. Normal action of valve control is
defined as valve open at 100% of the valve position’s full scale, and valve closed at 0%. Reverse action of
valve control is defined as valve open at 0% of the valve position’s full scale and valve closed at 100%
