Micromod MOD: 1800P - MOD 30ML Identity Module (Version 2) System, I/O and Communications Functions - Manual (Page 125)

Logic Functions - Book 1
DIGITAL INPUT MODULE BLOCK (DIM)
5-5
5.2.1 Digital Input Module Block Operation
The Digital Input Module block is a data repository for the instrument. One module block
services one module and as many other digital input function blocks as required can be
connected. All digital inputs are buffered in one of five possible task state tables. Process
input and output routines use these tables to pass data between the module blocks which run
at the base scan rate (50 msec) and the process algorithm blocks which run at the scan group
interval configured for the task.
For inputs, all valid data for a single instrument (up to 32 digital input modules) is read and
stored in these blocks every base scan cycle. The process input algorithm block (DI)
connected to the module block will filter the data according to the parameters found the DI
block’s configuration.
Digital input module blocks generate a diagnostic error based upon the unsuppressed I/O
mismatch condition. Events are reported for setting the block to auto or manual, the I/O
mismatch, or state changes.
During a warm or cold start condition, a pre-run read of the module value is performed to
initialize the field result, result, conditioning and I/O task buffer values. If no I/O
communications error is encountered these values are forward initialized and their qualities
marked GOOD, otherwise the previous values are held and their qualities marked BAD. If the
mode is MANUAL, the pre-run read value gets loaded into the field result, the result remains
at its previous value and its quality marked GOOD.