Mitsubishi Electronics FX5 ユーザーズマニュアル

19  BUILT-IN I/O FUNCTION
19.1  High-speed Counter Function

This section describes details about the special registers used with the high-speed counters.

These devices store the current values of the high-speed counters.

■Corresponding devices

The device numbers corresponding to each channel are as follows.

■Description

These devices stores the current values of the high-speed counters.
These are signed 32-bit ring counters. (Upper limit value+1 changes to 

 lower limit value, lower limit value-1 changes to  

upper limit value.)
When the ring length is not set, lower limit value: -2147483648, upper limit value: 2147483647.
When the ring length is set, lower limit value: 0, upper limit value: ring length-1.

 • To rewrite the current value, use the HCMOV instruction and transfer the desired value. However, this is the 

upper limit when set to a value that exceeds the upper limit value, and this is the lower limit value when set 
to a value that is less than the lower limit value.

 • If the current value falls outside the ring length range when the ring length is set, the upper and lower limit 

values of the ring length are ignored and the current value is used.

 • The current value is retained even when the power is OFF.

■Update timing

The current value of the high-speed counter is updated in END processing or when the HCMOV instruction is executed. 
Further, when the FX3 compatible high-speed counter function is valid, the value is updated also when UDCNTF instruction is 
executed.

■Clear timing

The timing when the device is cleared is as follows.
 • Cleared by the DHCMOV instruction
 • When the RST LC instruction executes ON (only when the FX3 compatible high-speed counter function is valid and the 

applicable LC device is used)

 • Power ON, reset, RUN→STOP (only when the FX3 compatible high-speed counter function is valid and the applicable LC 

device is used)

These devices store the maximum values of the high-speed counters.

■Corresponding devices

The device numbers corresponding to each channel are as follows.

■Description

These devices stores the maximum values of the high-speed counters.

 • To rewrite the maximum value, only the HCMOV instruction can be used.
 • These devices also operate when the FX3 compatible high-speed counter function is valid.

SD4501, 
SD4500

SD4531, 
SD4530

SD4561, 
SD4560

SD4591, 
SD4590

SD4621, 
SD4620

SD4651, 
SD4650

SD4681, 
SD4680

SD4711, 
SD4710

SD4503, 
SD4502

SD4533, 
SD4532

SD4563, 
SD4562

SD4593, 
SD4592

SD4623, 
SD4622

SD4653, 
SD4652

SD4683, 
SD4682

SD4713, 
SD4712