IDEC MicroSmart - Manual (Page 128)

5: S PECIAL F UNCTIONS
5-8 « FC4A M ICRO S MART U SER ’ S M ANUAL »
Special Data Registers for Single-phase High-speed Counters (All-in-One Type CPU Modules)
Single-phase High-speed Counter Specifications (All-in-One Type CPU Modules)
High-speed Counters on Slim Type CPU Modules
Slim type CPU modules have four high-speed counters; HSC1 through HSC4. HSC1 and HSC4 can be used as a two-
phase or single-phase high-speed counter. HSC2 and HSC3 are single-phase high-speed counters. All high-speed counter
functions are selected using the Function Area Settings in
WindLDR .
High-speed Counter Operation Modes and Input Terminals (Slim Type CPU Modules)
For wiring high-speed counter input signals, use twisted-pair shielded cables.
Two-phase High-speed Counters HSC1 and HSC4 (Slim Type CPU Modules)
Two-phase high-speed counter HSC1 or HSC4 operates in the rotary encoder mode, and counts up or down input pulses to
input terminals I0 or I6 (phase A) and I1 or I7 (phase B), respectively. When the current value overflows 65535 or under-
flows 0, a designated comparison output turns on. Any output terminal available on the CPU module can be designated as
a comparison output. When input I2 or I5 (reset input) is turned on, the current value is reset to a predetermined reset
value, and the two-phase high-speed counter counts subsequent input pulses starting at the reset value.
Two special data registers and six special internal relays are assigned to control and monitor each two-phase high-speed
counter operation. The current value is stored in data register D8045 or D8051(current value) and is updated every scan.
The value stored in D8046 or D8052 (reset value) is used as a reset value. When a high-speed counter reset input (I2/I5 or
M8032/M8046) is turned on, the current value in D8045 or D8051 is reset to the value stored in D8046 or D8052.
The two-phase high-speed counter is enabled while gate input special internal relay M8031 or M8045 is on and is disabled
while M8031 or M8045 is off. When current value overflow or underflow occurs while counting up or down, special inter-
nal relay M8131/M8136 or M8132/M8137 turns on in the next scan, respectively. At this point, the D8045 or D8051 cur-
rent value is reset to the D8046 or D8052 reset value for the subsequent counting cycle. When comparison output reset
special internal relay M8030 or M8044 is turned on, the designated comparison output is turned off. When reset input I2 or
I5 is turned on to reset the current value, reset status special internal relay M8130 or M8135 turns on in the next scan.
When reset input special internal relay M8032 or M8046 is turned on, M8130 or M8135 does not turn on. See page 5-13.
Note: When using input I2 or I5 as a phase Z input, set 0 to reset value special data register D8046 or D8052, respectively.
Description
High-speed Counter No.
Updated Read/Write
HSC1 HSC2 HSC3 HSC4
High-speed Counter Current Value D8045 D8047 D8049 D8051 Ever y scan Read only
High-speed Counter Preset Value D8046 D8048 D8050 D8052 — R/W
Maximum Counting Frequency
HSC1: 20 kHz
HSC2 through HSC4: 5 kHz
Counting Range 0 to 65535 (16 bits)
Operation Mode Adding counter
Gate Control Enable/disable counting
Current Value Reset
Current value is reset to 0 when the current value reaches the preset value or when
reset input I2 (HSC1 only) or a reset input special internal relay is turned on.
Status Relays Special internal relays for indicating high-speed counter statuses.
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.
High-speed Counter No. HSC1 HSC2 HSC3 HSC4
Input Terminal I0 I1 I2 I3 I4 I5 I6 I7
Two-phase
High-speed Counter
Phase A Phase B
Reset Input
(Phase Z)
— —
Reset Input
(Phase Z)
Phase A Phase B
Single-phase
High-speed Counter
—
Pulse
Input
Reset Input
Pulse
Input
Pulse
Input
Reset Input —
Pulse
Input