Memory Map Organization; Modbus Memory Map - GE 869 Communications Manual

CHAPTER 11: MODBUS MEMORY MAP

Memory Map Organization

MODBUS memory map

Modbus Hex Description
Address Address
Actual Values
Product Information
30001 0x0000 Product Code
30002 0x0001 Hardware Revision
30003 0x0002 Firmware Version
869 MOTOR PROTECTION SYSTEM – COMMUNICATIONS GUIDE
User Map Address
User Map Address 21,22
User Map Address 23,24
User Map Address 25,26
User Map Address 27,28
The 869 supports 32-bit Modbus items to be configured in the user map. When such an
address is configured in the user map for example at user map address 1, user map
address 2 is also consumed by the same item irrespective of the address assigned in
address 2.
The 869 Memory Map describes all the data registers that can be accessed via serial
communications. The Memory Map address range is grouped into several categories as
outlined in the following table. All memory map locations are two byte (16 bit) values. The
remaining pages of this chapter list all locations of the Memory Map. Addresses for all
locations are shown in hexadecimal. Consult the range, step, units, and the data format
(listed after the memory map) to interpret register values.
Many Modbus communications drivers add 40001d to the actual address of the register
addresses. For example, if address 0h was to be read, then 40001d would be the address
required by the Modbus communications driver; similarly, if address 320h (800d) was to be
read, then 40801d would be the address required by the Modbus communications driver.
Table 11-2: Memory Map Organization
Memory Map Section Address Range
Product ID 0000h to 007Fh
Commands 0080h to 00FFh
User Map 0100h to 01FFh
Actual Values 0200h to 0FFFh
Setpoints 1000h to 1FFFh
Event Recorder, Trace 2000h to 2FFFh
Memory, and Data Logger
Reserved 3000h to 3FFFh
Factory Service Data 4000h to FFFFh
Min
0
0
0
Description
Ic
In
Iavg
Ig
Description
Identification and revision information.
Substitute command locations. Read and write
access.
User Map Values and Addresses. See the
previous section for details.
Actual values data. Read Only.
Setpoints data. Read and Write.
See relevant sections in this chapter for details.
Reserved for future use.
Reserved.
Max Step Units
65535 1
26 1
65535 1
MEMORY MAP ORGANIZATION
Modbus Address
31274 31275
31278 31279
31295 31296
31276 31277
Format Factory Size in
Code Default Words
F0 0 1
FC110 1 1
F2 140 1
11-3