Rockwell Automation 1404-M4_M5_M6_M8 Powermonitor 3000 User Manual, PRIOR to Firmware rev. 3.0 User Manual

Page 139

Publication 1404-UM001D-EN-E - October 2004

Data Logging 7-7

This read/write table contains 22 integer elements including the
following:

• Password: A valid password is required to write a user comment;

write a value of -1 to select a record for read-back

• Write type: 0 selects a record for readback; 1 selects a record for

writing a new user comment (prevents inadvertent creation of a
user comment)

• DeviceNet unique write identifier
• Text block number: 1 for the first 26, or 2 for the last 24

characters in the user comment string

• Event record internal identifier: -1 creates a new event; 0 -

32767 selects the corresponding event record to write; see
below

• Timestamp of user-entered event
• Text character pair data: see below

The Event record internal identifier value between 0 and 32767
selects the corresponding existing event. A read of Table A.27 returns
the Event log internal identifier in element 1 and the Event text
available flag in element 17.

Each Text character pair element in the table contains two characters
expressed in ASCII standard coding. On a write, Text character pair
data will be written into the specified Block number for the event
record unless a user comment already exists for the selected record.

You may calculate the position of the characters in the user comment
as follows:

Example: the value 3345 hex in character pair #2, block #2,
corresponds to “3” and “E” in character positions 28 and 29 in the user
comment string.

Reading a User Comment using communications

You read a User Comment using a variation of the indexed read
method. Typically, a client reads the Event Log and, when it finds the
Event text available flag set in the results table, runs a routine to read
the user comment. Two writes to, and two reads of Table A.50 Event
Log Text are needed to read the entire user comment. The first write
contains these elements:

Text Block #

–

(

) 26

•

(

)

Text Character Pair #

(

)