Availability Of Dynamic Data; Object Specific Services - Allen-Bradley 1444-TSCX02-02RB User Manual

Availability of Dynamic Data

Immediately after power cycle or configuration download, dynamic data takes
some time to become available as internal sample buffers must be populated
based on the new time configuration.
In most cases, the delay can be a few seconds. However, for configurations with
low sample rates, the delay could be several minutes.

Object Specific Services

Table 117 - Object Specific Services
Service Implementation
Code
Class Instance
0x4B x x
0x4C - x
(1) Data types that consist of multiple bytes are transferred in little-endian format (least significant byte first).
A data communication session starts at the first service request and ends after
the final response of the exchange. However, the session is subjected to an
(inactivity) timeout of 30 seconds.
Rockwell Automation Publication 1444-UM001D-EN-P - June 2018
Service Name Description of Service
Alarm Buffer Force the alarm data to be saved as if an alarm has
Trigger occurred. This save is intended to be used when an
alarm or event external to the DMx-M has occurred.
CM Record Specify the Record Request parameters (defined in the
(1)
Request following section). Since the records can be large and
the request can be for many records, the Record
Request usually has to be sent multiple times.
CIP Objects Appendix A
389