Honeywell VRX180 user manual Suggested Scan Rates, Inputs Scan Rate Control

Programming Function Blocks and Features

4.24 Scan Rate

Scan rate is the time required to measure inputs, execute function blocks (AI, Loops, AO, DI, DO, CV, etc.) and update outputs. It is also known as the machine cycle, scan cycle, and update rate.

The Scan Rate prompt lets you set the scan rate of the instrument to a value slower than the maximum rate allowed by the hardware. The hardware will determine the default scan rate. Allowable entries are 250 milliseconds, 500 milliseconds, 1 second, 2 or 3 seconds. 250 ms rate is only available on 4 input units.

We recommend the following scan rates for the following configurations.

Table 4-70 Suggested Scan Rates

Inputs	Scan Rate	W/Control
Up to 4	250 msec	500 msec
Up to 12	500 msec	1 sec
Up to 16	750 msec	1 sec
Up to 24	1 sec	1.5 sec
Up to 32	1.5 sec	2 sec
Up to 44	2.0 sec	2 sec
Up to 48	3.0 sec	3 sec

NOTE

These are suggested scan rates. In general, if your instrument responds too slowly, use a slower (higher) scan rate. You can use a faster (lower) scan rate than suggested here, but be aware of possible sluggish display and button response time.

164 Video Recorder – User Manual