Yaskawa Motion Control G7 Drive Software - Manual (Page 34)

Date: 05/16/08, Rev: 08-05 Page 34 of 38 TM.G7SW.117
5.11 32-bit Distance from Home
The distance from home (including home offset) can be monitored by reading Modbus addresses 0734h and
0735h and combining them into one number as shown in example 2. This number represents the number of
encoder quadrature counts (encoder PPR * 4) from the home + home offset position, and is only valid after a
homing routine has been completed. In order to ensure that the data from the two 16 bit registers remain
synchronized, they should be read using a “Read Multiple” (03h) Modbus command.
Example 2 - Combine two 16-bit words into a single 32-bit number:
Low Word (0734h) = 12,345
High Word (0735h) = 9,876
Step 1: Multiply the High Word by 65,536.
High Word * 65,536 = 9,876 * 65,536 = 647,233,536
Step 2: Add the Low Word to the result of Step 1.
Low Word + Step 1 Result = 12,345 + 647,233,536 = 647,245,881
5.12 Motion Control Modbus Status Register
The Modbus register 0736h is added to provide a status word that encompasses the status of the drive’s digital
outputs (programmed by the H2-0x parameters) and all of the motion control specific logic outputs.