Omron CJ1W-CT021 Operation Manual page 194

Application Restrictions
The External Interrupt Task buffer stores up to 30 requests.
For functions that cannot guarantee a response time of 0.5 ms or shorter, the
approximate response time will be as follows:
Response time = 0.5 ms + function execution time.
External Control Inputs and Z-signal Inputs take approximately 300 µs, and external
interrupt tasks take 10 µs per interrupt.
Refer to Appendix E "IORF and IOWR/IORD-instruction Execution Times" for
information on execution times for IORF and IOWR/IORD-instructions.
174
Restriction Reference
5-2-5 "Interrupt FIFO full error"
Appendix C "Description of the
Response Time"
Section D