Reference MVI56-DEM
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ControlLogix Platform
Honeywell DE Communication Module
ProSoft Technology, Inc.
Page 47 of 80
March 6, 2008
Step Description
Upload
Populates write database with that of the Smart Transmitter (via the read
database in the processor). Upload may be a continuous loop if the module is to
be configured in an un-secure mode. Otherwise, the Upload should only be
initiated by a user. Ladder logic must support this feature. The operation only
interacts with the processor and does not affect the operation of the MVI module.
Download
Download populates the Smart Transmitter with the values in the write database
from the processor. First download will put the Smart Transmitter in the DE mode
(future) (if it is not already)
5.2.3 Reading from Honeywell Smart Transmitters
The ProSoft MVI56-DEM module allows the processor to read the real time data,
the status data, and the configuration parameters in the Smart Transmitter's
database. An overview of the data that is available from a transmitter follows (A
detailed listing and description of the data is in the Reference chapter of this
manual):
Type Description
Real Time
PV Value (Last Good Value and NaN value)
SV Value (Last God Value and NaN value)
Status
Module Status: Health indication
Data Base Mismatch Status flags
PV Update Counter
SV Update Counter
Communication
Error Counter
Status Messages: ASCII
Configuration Function:
Download/Upload
Tag Name: ASCII
Serial Number: ASCII
DE Configuration: Data base mode
Damping
Value
PV
Characterization
Sensor
Type
PV Number (channel # on MV transmitter)
Number of PVs: (# of channels on MV Transmitter)
Upper Range Value: URV
Lower Range Value: LRV
Upper Range Limit: URL
Lower Range Limit: LRL
The Status and Configuration values are being received from the Smart
Transmitter on a continuous basis to the DEM. The DEM will not actually receive
these values until a complete database has been acquired from the instrument.
This cycle can take anywhere from 15 to 90 seconds, depending on the
instrument type. After the database is read into the DEM module, the cycle
automatically starts over again. In this fashion the DEM module, and therefore
the PLC Read Database, are being completely updated on a regular basis.
