Plc Path; Sync Time With Plc; Status Print Interval; Tags - ProSoft Technology MVI56E-LDM-MQTT Quick Start Manual

MVI56E-LDM-MQTT ♦ MQ Telemetry Transport
ControlLogix® Platform

9.1.2 PLC Path

This defines the connection string to connect to the PLC.

9.1.3 Sync Time with PLC

A flag indicating if the system time should be synchronized with the PLC.
Value
0
1
2

9.1.4 Status Print Interval

This setting is optional.
MQTT Broker periodically checks the connection status. Messages are written to the log
system on every status change. Additional status messages are written at the interval
defined in this parameter, whether or not the status has changed.
The Default value is 10 (seconds).

9.1.5 Tags

The following table includes tags that are defined in the PLC with the settings to map
them to MQTT messages:
Parameter
Tag
DataType
ScanRate
Access
Topic
Subscribe Topic
The name of the MQTT topic on which MQTT-LDM subscribes to receive messages with
new values written to the PLC for this tag.
If this option is omitted, or has an empty value, the system uses the same topic used for
publishing. In this case, the MQTT-LDM receives its own publish messages as well.
Although the received value is written only if it is different than the last read value, there
is no guarantee that an older value is not written due to race conditions. It is
recommended to use a different Subscribe topic name, rather than a Publish topic name.
In the sample configuration files, the Subscribe topic name is composed by adding /Set
at the end of the Topic name.
After changing the configuration file, the process mqtt-ldm-sample-app-mvi56e must
be re-started.
ProSoft Technology, Inc.
Description
Default value. Synchronize once, if current system year is less than 2019, which is usually case
after system restart. This helps prevent a system reset when PLC time is not set.
Synchronize one time after the first successful connection to the PLC.
Synchronize after every successful connection to the PLC.
Description
Name of the tag in PLC. Defined for MVI56E-LDM only.
Data Type of the tag in the PLC. Possible values are: BOOL, SINT, INT, DINT, LINT, USINT,
UINT, UDINT, ULINT, REAL, LREAL, BYTE, WORD, DWORD, LDWORD, STRING82
Defines how often the tag value is read from the PLC, in milliseconds.
Defines if the tag is read-only (value is RD), or readable and writable (value is RDWR).
Name of the MQTT topic for which the data values are published.
Optional. Ignored if the Access field is set to RD (read only)
Configuration File Details
Quick Start Guide
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