7 Application Instructions API 50-99 v) High speed counter and high speed comparator: X10 X11 vi) Explanations on high speed counter and high speed comparator: (1) When DHSCS and DHSCR instructions use the high speed counter (C243/C245/C250/C255), they can only use the set values of 2 groups of high speed comparative instructions. Assume that a group of comparative instruction DHSCS D0 C243 Y10 is already in use, you can only set another group DHSCR D2 C243 Y10 or DHSCS D4 C245 Y10. (2) When DHSZ instruction use the high speed counter (C243/C245/C250/C255), it can only use the set value of a group of comparators.
(3) The number of set values in a high-speed comparative instruction offered in SA/SX series MPU will not decrease becasus of the addition of the new high speed counters. (4) If the high-speed comparative instruction DHSCS requires a high-speed reponse output, it is suggested that you use Y10 or Y11 for the output. If you use other general devices for the output, there will be delay of 1 scan period. For example, when in I0x0 interruption, C234 will correspond to I020, C245 to I040 and C250/C255 to I060. (5) The high-speed comparative instruction DHSCR can clear output devices and counter devices, but only the counters used by the same instruction, e.g. DHSCR K10 C243 C243.
This function can only applied in the four special high speed counters C243, C245, C250 and C255. e) Counting modes: i) The 2-phase 2 inputs counting mode of the high speed counters in ES/EX/SS (V5.5 and above) and SA/SX/SC series MPU is set by special D1022 with normal frequency, double frequency and 4 times frequency modes. The contents in D1022 will be loaded in in the first scan when PLC is switched from STOP to RUN. DVP-PLC APPLICATION MANUAL 7-9 Output reaches comparative value C243 Set value 10 ra to r a p C245 m Set value 11 C o C250 High-speed comparison instruction C255 Output reaches comparative value C250 Device No.
Function D1022 Setting up the multiplied frequency of the counter D1022 = K1 Normal frequency mode selected D1022 = K2 or 0 Double frequency mode selected (default) D1022 = K4 4 times frequency mode selected