Specifications

Functional Overview
ProLinx Communication Gateways, Inc. 7
HART Master Protocol Drive Manual
August 17, 2004
1.2.1 HART Channel Driver Access to Database
The following diagram details the flow of data between the HART channel drivers and the
internal database.
Virtual
Database
Command
List
Other
Driver
HART
Driver
Slave
Device
Databases Other
Protocol
HART
Master
HART
Slaves
Request
Response
Read
Read for
Write Command
Write for Read
Command
Write
Read
The HART Master driver uses the database in two ways:
1. A read command issued to a slave device by the master driver will return the
slave data into the internal database
2. A write command issued to a slave device by the master driver use the data in
the internal database to write to the slave device
In addition to data from the master HART channels, detailed status and error information
generated by the module can also be mapped into the internal database.
1.2.2 Auto-Polling
This feature is enabled by setting the AUTO-POLL CODE (in the configuration file) to a
value of P (point-to-point) or M (multidrop). If the value N is entered for the parameter,
the auto-poll feature is disabled. When the feature is disabled, the channel will only
execute the commands enabled in the user command list. When the auto-polling mode
is enabled, the module will automatically acquire data from the HART instruments
attached to a channel without the use of user commands. If user commands are present
and enabled when the feature is enabled, they will also be executed independent of auto-
polling.
With the auto-poll feature enabled, the module automatically generates the following
HART commands and stores the data in the module’s database at the user-specified
location:
CMD DESCRIPTION
0 Read Unique Identifier
3 Read Current and Four Dynamic Variables
13 Read Tag, Descriptor and Date
14 Read PV Sensor Information
15 Read Output Information