Mitsubishi Electric MELSEC iQ-R Series User Manual page 96

Faulty operation during synchronization
The causes of the faulty operation during synchronization are as follows:
• Cycle crossing (Page 94 Operation when a cycle crossing occurs)
• Cycle skipping (Page 96 Operation when a cycle skip occurs)
• Synchronization loss (Page 97 Operation when a synchronization loss occurs)
■Operation when a cycle crossing occurs
The phenomena that D/A conversion is processed across the inter-module synchronization cycle due to the operation timing
of the inter-module synchronous interrupt program (I44) is called "cycle crossing". When a cycle crossing has occurred, an
inter-module synchronization cycle crossing over error (error code: 2600H) occurs. The synchronization status of the D/A
converter module when an error occurs becomes Synchronization stop or Synchronization continue depending on the setting
of 'Output setting during synchronization error' (Un\G9532).
The following shows the operation of the D/A converter modules of when a cycle crossing has occurred.
• When 'Output setting during synchronization error' (Un\G9532) is set to Synchronization continue (0)
Inter-module
synchronization cycle
Inter-module synchronous
interrupt program
'CH1 Synchronization
digital value' (Un\G9500)
Analog output value
in CH1
'Synchronization status
monitor' (Un\G9600)
Inter-module synchronous interrupt program (I44)
(1) A cycle crossing occurs since the D/A conversion has been processed across the inter-module synchronization cycle.
(2) Since the cycle crossing has occurred, 2A synchronization digital value is ignored. 3A synchronization digital value is converted to analog in the next inter-
module synchronization cycle, and output in analog.
1 FUNCTIONS
94
1.15 Inter-Module Synchronization Function
Inter-module synchronization cycle
1A
D/A
conversion
Inter-module synchronization target (during synchronization) (2)
2A
(1)
D/A D/A
conversion conversion
Analog output value of 1A
3A
Analog output
value of 3A
(2)