Eaton IQ 150S, User & Installation Manual

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IM02601006E www.eaton.com B-8
IQ 150S/250S B: Modbus Map
While the Register List describes what to log, the Item Descriptor List describes how to interpret
that information. Each descriptor describes a group of register items, and what they mean.
Each descriptor is composed of 2 parts:
• Type: The data type of this descriptor, such as signed integer, IEEE floating point, etc. This is the
high nibble of the descriptor byte, with a value in the range of 0-14. If this value is 0xFF, the
descriptor should be ignored.
0 ASCII: An ASCII string, or byte array
1 Bitmap: A collection of bit flags
2 Signed Integer: A 2's Complement integer
3 Float: An IEEE floating point
4 Energy: Special Signed Integer, where the value
is adjusted by the energy settings in the meter's
Programmable Settings.
5 Unsigned Integer
6 Signed Integer 0.1 scale: Special Signed Integer,
where the value is divided by 10 to give a 0.1
scale.
7-14 Unused
15 Disabled: used as end list marker.
• Size: The size in bytes of the item described. This number is used to determine the pairing of
descriptors with register items.
For example: If the first descriptor is 4 bytes, and the second descriptor is 2 bytes, then the first
2 register items belong to the 1st descriptor, and the 3rd register item belongs to the 2nd
descriptor.
NOTE:
As can be seen from the example, above, there is not a 1-to-1 relation between the reg-
ister list and the descriptor list. A single descriptor may refer to multiple register items.
Register Items Descriptors
0x03C7/ Float, 4 byte