User manual OMRON CJ2 CPU UNIT SOFTWARE

[. . . ] CJ2 CPU Unit Software USER'S MANUAL OMRON, 2008 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form, or by any means, mechanical, electronic, photocopying, recording, or otherwise, without the prior written permission of OMRON. No patent liability is assumed with respect to the use of the information contained herein. Moreover, because OMRON is constantly striving to improve its high-quality products, the information contained in this manual is subject to change without notice. [. . . ] A value of 0000 hex is set when the power is turned ON and this value is automatically incremented by 1 every 100 ms. The value returns to 0000 hex after reaching FFFF hex (6, 553, 500 ms), and then continues to be automatically incremented by 1 every 100 ms. A value of 0000 hex is set when the power is turned ON and this value is automatically incremented by 1 every second. The value returns to 0000 hex after reaching FFFF hex (65, 535 s), and then continues to be automatically incremented by 1 every second. A1 A2 Note When the operating mode is changed to RUN mode, automatic incrementing by 1 will continue. Example: The time interval between processing A and processing B can be calculated in increments of 10 ms by calculating the difference between the value in A0 for processing time A and the value in A0 for processing time B without using timer instructions. 10-6 CJ2 CPU Unit Software User's Manual 10 CPU Unit Functions 10-2 Cycle Time/High-speed Processing 10-2 Cycle Time/High-speed Processing 10-2-1 Minimum Cycle Time A minimum (or fixed) cycle time can be set in PLCs. Variations in I/O response times can be eliminated by repeating the program with a fixed cycle time. The minimum cycle time (0. 1 to 32, 000 ms) is specified in the PLC Setup in 0. 1-ms units. Minimum cycle time Minimum cycle time Minimum cycle time (Effective) (Effective) (Effective) 10 10-2-1 Minimum Cycle Time Actual cycle time Actual cycle time Actual cycle time If the actual cycle time is longer than the minimum cycle time, the minimum cycle time function will be ineffective and the cycle time will vary from cycle to cycle. Minimum cycle time Minimum cycle time Minimum cycle time (Effective) Actual cycle time (Effective) Actual cycle time (Effective) Actual cycle time PLC Setup When using the CX-Programmer, make the settings on the Timings/Synchronous Tab Page. CJ2 CPU Unit Software User's Manual 10-7 10 CPU Unit Functions Additional Information When the CPU Unit is operating in MONITOR mode, the minimum cycle time (constant cycle time) can be changed from the PLC Cycle Time Dialog Box of the CX-Programmer. (This function is supported only by CJ2H CPU Units with unit version 1. 1 or later and CJ2M CPU Units. ) For details, refer to 12-1 Monitoring the Cycle Time. 10-2-2 Maximum Cycle Time If the cycle time exceeds the maximum cycle time setting, the CPU Unit will stop operation. The default maximum cycle time is 1 s. PLC Setup When using the CX-Programmer, set the maximum cycle time in the Watch Cycle Time Field on the Timings/Synchronous Tab Page. Auxiliary Area Flags and Words Name Cycle Time Exceeded Flag Address A401. 08 Description A401. 08 will be turned ON if the cycle time exceeds the watch cycle time setting. 10-8 CJ2 CPU Unit Software User's Manual 10 CPU Unit Functions 10-2 Cycle Time/High-speed Processing 10-2-3 Monitoring the Cycle Time Every cycle, the Auxiliary Area stores the maximum cycle time in A262 to A263 and the present cycle time in A264 to A265 and A266 to A267. Auxiliary Area Flags and Words Name Maximum Cycle Time (0. 1-ms increments) Address A262 and A263 Description The maximum cycle time in 0. 1-ms increments is stored every cycle in 8-digit hexadecimal in the following range: 0 to 429, 496, 729. 5 ms (0 to FFFF FFFF) The lower digits are stored in A262 and the upper digits are stored in A263. Present Cycle Time (0. 1-ms increments) A264 and A265 The present cycle time in 0. 1-ms increments is stored every cycle in 8-digit hexadecimal in the following range: 0 to 429, 496, 729. 5 ms (0 to FFFF FFFF) The lower digits are stored in A264 and the upper digits are stored in A265. Present Cycle Time (0. 01-ms increments) A266 and A267 The present cycle time value in 0. 01-ms increments is stored every cycle in 8-digit hexadecimal in the following range: 0 to 42, 949, 672. 95 ms (0 to FFFF FFFF) The lower digits are stored in A266 and the upper digits are stored in A267. 10 10-2-3 Monitoring the Cycle Time The CX-Programmer can be used to read the average cycle time for the last 8 cycles. Additional Information The following methods are effective ways to reduce the cycle time in CJ-series PLCs: · Put tasks that aren't being executed in WAIT status. · Use with JMP(004), CJP (510), or CJPN (511) together with JME(005) to jump program sections that do not need to be executed. 10-2-4 High-speed Inputs When you want to receive pulses that are shorter than the cycle time, use the CJ1W-IDP01 High-speed Input Unit. The high-speed inputs can receive pulses with a pulse width (ON time) of 0. 05 ms for the CJ1W-IDP01 High-speed Input Unit. High-speed Input Unit or High-density Input Unit CJ1W-IDP01: 0. 05 ms Inputs that are input to internal memory are cleared when the inputs are refreshed. CJ2 CPU Unit Software User's Manual 10-9 10 CPU Unit Functions 10-2-5 Background Execution Table data processing (such as data searches) and text string processing (such as text string searches), require time to execute, and can create large fluctuations in the cycle time due to the extended amount of time required to execute them. Background execution (time slicing) can be used to execute the following instructions over several cycles to help control fluctuations in the cycle time. The PLC Setup enables setting background execution for each type of instruction. · Table data processing instructions · Text string processing instructions · Data shift instructions (ASYNCHRONOUS SHIFT REGISTER only) Setting background execution for the above instructions can help control temporary increases in the cycle time. Without Background Processing MAX With Background Processing Long execution time Longer cycle time when MAX is executed. MAX Execution only started. Background execution Executed over several cycles using time slicing. Precautions for Correct Use Background processing is not performed in interrupt tasks for CJ2H CPU Units when high-speed interrupts are enabled in the PLC Setup. An instruction processing error will occur. 10-10 CJ2 CPU Unit Software User's Manual 10 CPU Unit Functions 10-2 Cycle Time/High-speed Processing Applicable Instructions Background processing will not be performed for the following instructions when they are used in function blocks. They will be executed using normal processing. Group Table Data Processing Instructions Instruction DATA SEARCH SWAP BYTES Find Maximum Instructions Mnemonic SRCH SWAP MAX MAXL MAXF MAXD Find Minimum Instructions MIN MINL MINF MIND SUM FRAME CHECKSUM Data Shift Instructions Text String Processing Instructions ASYNCHRONOUS SHIFT REGISTER MOVE STRING CONCATENATE STRING GET STRING LEFT GET STRING RIGHT GET STRING MIDDLE FIND IN STRING STRING LENGTH REPLACE IN STRING DELETE STRING EXCHANGE STRING CLEAR STRING INSERT INTO STRING SUM FCS ASFT MOV$ +$ LEFT$ RGHT$ MID$ FIND$ LEN$ RPLC$ DEL$ XCHG$ CLR$ INS$ 10 10-2-5 Background Execution CJ2 CPU Unit Software User's Manual 10-11 10 CPU Unit Functions Procedure 1 To enable background execution for the required instructions, make the background execution settings on the Settings Tab Page in the PLC Settings Dialog Box from the CX-Programmer. 2 Set the logical port number to be used for background execution in the PLC Setup. This port number will be used for all instructions processed in the background. Background execution for an instruction can thus not be started if background execution is already being performed for another instruction. Use the Communications Port Enabled Flag to control instructions specified for background execution so that no more than one instruction is executed at the same time. If an instruction for which background execution has been specified is executed, execution will only be started in the cycle in which the execution condition was met and execution will not be completed in the same cycle. [. . . ] 10-6 Power Interruption Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4 Total Power ON Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5 Total Power ON Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5 trace memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ]