6. Series 8 I/O
Configuration
6.10. Defining Digital Output Channel Blocks
198
Series 8 I/O User's Guide
R500
Honeywell
April 2017
Determining Initialization Request Flag
The request to initialize a Digital Output channel is accomplished through the INITREQ
or PWMINITREQ parameters.
Table 54 Digital Output channel initialization
The following
is set to ON
And
INITREQ
Control strategies in Experion cannot manipulate the output.
Device Control blocks and Position Proportional control
algorithms are automatically forced to initialize when outputting to
a Digital Output channel.
When one or more of the following is true:
the IOMSTATE is IDLE, or
PTEXECST is INACTIVE
channel MODE is set to MAN, or
there is a soft failure and the point is not working
Note
: Device Control blocks and Position Proportional control
algorithms are automatically forced to initialize when outputting to a
Digital Output channel in which INITREQ is ON.
Determining Modes
The MODE parameter determines the operating mode for the channel block. The
following operating modes are applicable to the both Digital Output and Analog Output
channel blocks.
Manual (Man) - provides the operator or the program with direct control over the
output value of the channel, regardless of any continuous control strategy.
Cascade (CAS) - data point receives its output value from a primary data point.
TIP
Operators are only permitted to change MODE if MODEPERM is set to
Permit and REDTAG is set to off.
Determining Output Verification
Outputs are verified by periodically reading back the value on the output screw and
comparing the read back value with the database value. This includes an output wiggle
(for the safety system) to prove they are not stuck in any one state.