IDEC MicroSmart - Manual (Page 127)

5: S PECIAL F UNCTIONS
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Special Data Registers for Two-phase High-speed Counter (All-in-One Type CPU Modules)
Two-phase High-speed Counter Specifications (All-in-One Type CPU Modules)
Single-phase High-speed Counters HSC1 through HSC4 (All-in-One Type CPU Modules)
HSC1 can also be used as a single-phase high-speed counter as well as HSC2 through HSC4. The four single-phase high-
speed counters count input pulses to the input terminal allocated to each high-speed counter. When the preset value is
reached, a designated comparison output turns on, and the current value is reset to 0 to count subsequent input pulses.
Two special data registers and four special internal relays are assigned to control and monitor the single-phase high-speed
counter operation. The current value is stored in a special data register (current value) and is updated every scan. The value
stored in another special data register (preset value) is used as a preset value. When a reset input special internal relay is
turned on, the current value is reset to 0.
The single-phase high-speed counter is enabled while a gate input special internal relay is on and is disabled while the gate
input is off. When the current value reaches the preset value, a special internal relay (comparison ON status) turns on in the
next scan. At this point, the current value is reset to 0, and the value stored in a preset value special data register takes
effect for the subsequent counting cycle. When a comparison output reset special internal relay is turned on, the designated
comparison output is turned off.
In addition, only the single-phase high-speed counter HSC1 has reset input I2 and reset status special internal relay
M8130. When reset input I2 is turned on to reset the current value to 0, reset status special internal relay M8130 turns on
in the next scan. When reset input special internal relay M8032 is turned on, M8130 does not turn on. See page 5-14.
Special Internal Relays for Single-phase High-speed Counters (All-in-One Type CPU Modules)
Note: Special internal relays M8130, M8131, M8133, M8134, and M8136 go on for only one scan.
Description
High-speed Counter No.
Updated Read/Write
HSC1 HSC2 HSC3 HSC4
High-speed Counter Current Value D8045 — — — Ever y scan Read only
High-speed Counter Reset Value D8046 — — — — R/W
Maximum Counting Frequency 20 kHz
Counting Range 0 to 65535 (16 bits)
Operation Mode Rotar y encoder (phases A, B, Z)
Gate Control Enable/disable counting
Current Value Reset
Current value is reset to a given value when the current value over flows 65535 or
under flows 0, or when reset input I2 or reset input special internal relay M8032 is
turned on.
Control/Status Relays
Special internal relays are provided to control and monitor the high-speed counter
operation.
Comparison Output
Any output number available on the CPU module can be designated as a comparison
output which turns on when the current value reaches the preset value.
Output numbers on expansion output or mixed I/O modules cannot be designated as a
comparison output.
Description
High-speed Counter No.
ON Read/Write
HSC1 HSC2 HSC3 HSC4
Comparison Output Reset M8030 M8034 M8040 M8044 Turns off comparison output R/W
Gate Input M8031 M8035 M8041 M8045 Enables counting R/W
Reset Input M8032 M8036 M8042 M8046 Resets the current value R/W
Reset Status M8130 — — — Current value reset by I2 Read only
Comparison ON Status M8131 M8133 M8134 M8136 Preset value reached Read only