Mitsubishi FX3U Series User Manual

FX3U Series Programmable Controllers
User’s Manual - Hardware Edition
193
11 Use of High-speed Counters (C235 to C255)
11.7 Timing of Updating of Current Value and Comparison of Current Value
11
High-Speed Counters
12
Output Wiring
13
Wiring for Various Uses
14
Test Run, Maintenance, Troubleshooting
15
IInput/Output Powered Extension Units
16
Input/Output Extension Blocks
17
Extension Power Supply Unit
18
Other Extension Units and Options
19
Display Module
20
Terminal Block
11.7 Timing of Updating of Current Value and Comparison of Current Value
11.7.1 Timing of updating of current value
When a pulse is input to a high-speed counter input terminal, the counter increments or decrements. The
current value of the device is updated at the timing shown in the following table.
Therefore, when the hardware counter directly handles the current value of the high-speed counter for MOV
instruction or CMP instruction or an applied instruction (such as a contact comparison instruction), it uses the
current value updated at the timing shown in the following table. As a result, the counter operation is affected
by the scan time.
11.7.2 Comparison of current value
To compare and output the current value of a high-speed counter, the following two methods are available.
1. Use of comparison instruction (CMP), band comparison instruction (ZCP) or contact
comparison instruction
When the comparison results are necessary for counting operation, the value can be compared with time
*1
in
the main program by using HCMOV instruction just before a comparison command (CMP command/ZCP
command) or a contact comparison instruction.
*1. To compare the value with the high-speed counter's changing value and to change the output contact
(Y), use Comparison instruction for high-speed counters (HSCS/HSCR/HSZ/HSCT instruction).
2. Use of Comparison instruction for high-speed counters (HSCS/HSCR/HSZ/HSCT instruction)
Comparison instructions for high-speed counters (HSCS, HSCR, HSZ and HSCT instructions) perform
comparison and output the comparison results when the relevant high-speed counting operation. These
instructions have limitations on the number of times of use as shown in the following table.
When the output relay (Y) has been designated for comparison results, the ON/OFF status of the output is
affected directly until END instruction output is refreshed.
When the PLC is a relay output type, a mechanical delay in operation (approx. 10ms) is caused. Therefore,
use a transistor output type PLC.
*1. When HSZ or HSCT instruction is used, the maximum response frequencies and overall frequency of
all software counters becomes limited.
→ For the maximum response frequencies and overall frequency of software counters,
refer to Section 11.9.
Classification Timing of updating of current value
Hardware counter
OUT instruction of counter
HCMOV instruction
Software counter When count is input
Applied instruction Limitation on number of times of use of instruction
HSCS
Up to 32 times including the number of times of use of
HSCT instruction
HSCR
HSZ
*1
HSCT
*1
Only once

Mitsubishi FX3U Series Specifications

General

Brand	Mitsubishi
Model	FX3U Series
Category	Controller
Language	English