GE Industrial Solutions POWER LEADER ModBus Monitor - Manual (Page 61)

POWER LEADER Modbus Monitor
Appendix C – Register Data Formats
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Appendix C:
Register Data Formats supported by the Modbus Monitor
The following table describes the supported format codes of the Modbus Monitor. These are the only formats
available when either adding registers to a hybrid device or defining registers in a generic device. These data formats
appear in the Register Format pulldown list in the Configuration Tool’s Add Device Type Register dialog box.
A scaling factor will be applied to most register formats just before display. The user should use caution when
applying a scaling factor to a register since the results can be unexpected.
All register formats (except the floating point formats) will expect the data to be returned in the MSB-LSB order. For
example, a register with a ULONG format has a register value of 0x01020304. The data returned in the Modbus
packet is expected in the following bytes: 0x01 0x02 0x03 0x04. If the bytes are in any other order the Modbus
Monitor will not display the value correctly. The Modbus Monitor expects the two floating point formats to be in the
LSW-MSW order, where the LSW is the least significant word and MSW is the most significant word. For example,
a register with a FLOAT format has a register value of 1.000000 (0x3F800000). The data returned in the Modbus
packet is expected in the following byte order: 0x00 0x00 0x3F 0x80.
It should also be noted that the maximum number of characters which can be displayed in a data field on the Modbus
Monitor is 10. In the rare instances when a value exceeds 10 characters in length, the Monitor will truncate the least
significant digit(s) necessary to make the value 10 characters in length. For example, a value of -1000000000 would
be displayed as -100000000.
Format Description
BYTE The monitor will request one 16 bit register. The LS byte of the data received will be displayed as an unsigned
integer. The displayed values will range from 0 to 255. The selected scaling factor will be applied to the byte value.
UINT The monitor will request one 16 bit register. The data received will be displayed as an unsigned integer ranging from
0-65535.
INT The monitor will request one 16 bit register. The data received will be displayed as a signed integer ranging from
-32768 to 32767.
ULONG The monitor will request two 16-bit registers starting from the register address. The data received will be displayed as
an unsigned integer ranging from 0 to 4,294,967,295.
LONG The monitor will request two 16-bit registers starting from the register address. The data received will be displayed as
a signed integer ranging from -2,147,483,648 to 2,147,483,647.
FLOAT The monitor will request two 16-bit registers starting at the register address. The data is in a single precision IEEE
floating point format. The data received will be displayed to two decimal places of accuracy. Any value over 8 digits
will be displayed in scientific notation with a two decimal place accuracy.
UHEX The monitor will request one 16-bit register. The data received will be displayed as 4 hexadecimal digits.
MOD10000 The monitor will request one 32-bit register from the device. The data will be displayed as an integer. This format
supports the EPM 3710 and EPM 3720 modulus 10,000 format (please refer to the EPM documentation for the exact
data representation).
BCD The monitor will request one 16-bit register from the device. The data received will be displayed as an integer
ranging from 0000 to 9999. If any hex digit is out of the decimal range “Undefined” will be displayed.
UINT0FF The monitor will request one 16 bit register. The data received will be displayed as an unsigned integer ranging from
0-65535. A value of 0 in the register will be displayed as “OFF”.
INTOFF The monitor will request one 16 bit register. The data received will be displayed as a signed integer ranging from
-32768 to 32767. A value of 32767 in the register will be displayed as “OFF”.
FLOAT0FF The monitor will request two 16-bit registers starting at the register address. The data is in a single precision IEEE
floating point format. The data received will be displayed to two decimal places of accuracy. Any value over 8 digits
will be displayed in scientific notation with a two decimal place accuracy.