Eaton IQ 150S, User & Installation Manual

Page: 171 / 234

IM02601006E www.eaton.com B-17
IQ 150S/250S B: Modbus Map
NOTES:
• By itself this feature would not provide any advantage, as the same data will be returned RC
times. However, when used with auto-incrementing, this function condenses up to 8 requests
into 1 request, which decreases communication time, as fewer transactions are being made.
• Keep in mind that the contents of the response data is the block of data you requested, repeated
N times. For example, when retrieving log windows, you
normally request both the window index, and the window data. This means that the first couple
of bytes of every repeated block will contain the index of that
window.
• In the IQ 250S meter repeat counts are limited to 8 times for Modbus RTU, and 4 times for Mod-
bus ASCII.
The response for Function Code 0x23 is the same as for Function Code 0x03, with the data blocks
in sequence.
IMPORTANT!
Before using Function Code 0x23, always check to see if the current connection
supports it. Some relay devices do not support user defined function codes; if that is the case, the
message will stall. Other devices don't support 8 repeat counts.
B.5.4.3: Log Retrieval Procedure
The following procedure documents how to retrieve a single log from the oldest record to the new-
est record, using the "normal" record type (see
Scope
). All logs are retrieved using the same
method. See Section B.5.4.4 for a Log Retrieval example.
NOTES:
• This example uses auto-increment.
• In this example, Function Code 0x23 is not used.
• You will find referenced topics in Section B.5.3. Block Definitions.
• Modbus Register numbers are listed in brackets.
1. Engage the Log:
a. Read the Log Status Block.