12 - 64 
MELSEC-Q
12   CONTROL SUB FUNCTIONS 
 
[3]   Absolute position signal transmission procedure 
(1) Figure 12.36 shows the outline of the absolute position signal transmission 
procedure between the servo amplifier and the programmable controller 
system (CPU module, QD75, I/O module). 
Refer to the operation manual of the servo amplifier for details on the 
communication between the servo amplifier and the programmable controller 
system. 
(2) Errors during communication 
(a) If the system expires during communication, an error "ABS transmission 
time" (error code: 213) will occur. 
(b) If the transmission data causes a sum error, an error "ABS transmission 
SUM" (error code: 214) will occur. 
Refer to Section 15.3 "List of errors" for the remedial method to be taken 
when an error occurs. 
 
CPU module
[Dedicated
instruction]
Z.ABRST1
Z.ABRST2
Z.ABRST3
Z.ABRST4
Servo amplifier I/O module
Servo ON signal
ABS transmission
mode
ABS request
Transmission data
preparation completed
Current position
data
Data transmission
<Absolute position detection request>
QD75
<Current position data>
Md.20 
  Current feed value
Md.21 
  Machine feed value
ABS transmission
data bit 0
ABS transmission
data bit 1
 
 
Fig. 12.38 Absolute position signal transmission procedure 
 
 Refer to CHAPTER 14 "DEDICATED INSTRUCTIONS" for details of the dedicated 
instructions.