7 RG-TDMOD
Drive Setup & Operation
3
Data Representation - Internal and External
3.1 Register Format
All registers are 16 bits. The data within these registers can take on the following forms:
•
Individual bit commands (16 per register).
Example: Register #1 (Modbus Register #2).
•
Individual bit flags (16 per register).
Example: Register #22.
•
A chain of two 8 bit unsigned integers.
•
A 16 bit unsigned integer.
This unsigned integer could in turn represent many different types of data with various scaling
rules and units, which are defined by the DATA TYPE of the register.
3.2 Data Types
Data passed in registers across the Modbus communications link are always in INTERNAL units. The drive
itself may show the information in alternate DISPLAYED units. For Example: drive speeds are always stored
internally as tenths of a Hz but the drive may display that speed in whole Hz by dropping the tenth using
programmed conversion factors. Table 3 lists examples of the internal units used on the
Tmd
series.
Table 3:
Tmd
Series Internal Units
Type
Unit
Example
SPEED
.1Hz
60Hz = 600
TIME
.1Sec
30.0 Sec = 300
3.3
Tmd Drive Registers
Registers #0 through #50:
(Modbus Registers #1 to #51) Reserved for configuration and control
Registers #51 through #255
(Modbus Registers #52 to #256) Reserved for the drives’ programming
mode parameters. Programming Mode Parameters are the parameters
that can be accessed from the local keypad on the drive.
The entries in Table 6 are based on
Tmd
Drive Software # 1.20 (Parameter Configuration = 503). If a later
revision of software were to change register definitions, drive operation could be seriously affected. This will
be identified for a given drive by examining Register #50 (Parameter Configuration Number). The number
displayed at power up on drive display can also identify it. If it is not 503, writing to any register on the
drive MUST NOT BE ATTEMPTED unless your Controller has been setup to support the new configuration.