Mitsubishi Electric MELSEC iQ-F FX5 User Manual page 149

■Operation Description
The content of the operation when ON and when OFF is as follows.
Operation when ON
Underflow occurs
(Current value counted = -1 past maximum negative value)
• Does not operate when ring length setting is enabled.
• These devices also operate when the FX3 compatible high-speed counter function is valid.
■Update timing
The timing of device update is as follows.
ON
• Underflow occurs (This is updated with the END processing. When the FX3
compatible high-speed counter function is valid, the updating is made also
when UDCNTF instruction is executed ON.)
High-speed counter count direction monitor
Device for monitoring counter direction.
■Corresponding devices
The device numbers corresponding to each channel are as follows.
CPU module
CH1 CH2
SM4564 SM4565
High-speed pulse input/output module
First module
CH9 CH10
SM4572 SM4573
■Operation Description
The content of the operation when ON and when OFF is as follows.
Operation when ON
High-speed counter counting in direction whereby current value is reduced
(Down-counting)
These devices also operate when the FX3 compatible high-speed counter function is valid.
■Update timing
The timing of device update is as follows.
ON
Down-counting (This is updated with the END processing. When the FX3
compatible high-speed counter function is valid, the updating is made also
when UDCNTF instruction is executed ON.)
CH3 CH4
SM4566 SM4567
Second module
CH11 CH12
SM4574 SM4575
Operation when OFF
Underflow does not occur
OFF
• When OFF by the user
• Power ON, reset
• STOP/PAUSERUN
• SM50 turned ON
CH5 CH6
SM4568 SM4569
Third module
CH13 CH14
SM4576 SM4577
Operation when OFF
High-speed counter counting in direction whereby current value is increased
(Up-counting)
OFF
• Up-counting (When the FX3 compatible high-speed counter function is
valid, the updating is made also when UDCNTF instruction is executed ON.)
• Power ON, reset
• STOP/PAUSERUN
19 HIGH-SPEED INPUT/OUTPUT FUNCTION
19.1 High-speed Counter Function
CH7 CH8
SM4570 SM4571
Fourth module
CH15 CH16
SM4578 SM4579
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