Instruction Execution Times - Omron CQM1H - PROGRAM Programming Manual

Cycle Time
Note
Cycle Time Example
Process
Overseeing
Program execution
Cycle time calculation
I/O refresh
RS-232C port servicing
Peripheral port servicing
Serial Communications
Board servicing
Communications Unit
servicing
Cycle time
Note
7-3-2

Instruction Execution Times

1. The number of timers to undergo interrupt processing can be set in DM
6629 of the PC Setup. The default setting is for TC 000 through TC 015.
2. The PC Setup (DM 6655) can be used to disable detection of CYCLE TIME
OVER error.
3. The FALS 9F cycle monitoring time can be changed by means of the PC
Setup (DM 6618).
In this example, the cycle time is calculated for a CQM1H with 80 I/O points.
The I/O is configured as follows:
DC inputs: 48 points (3 words)
Bit outputs: 32 points (2 words)
The rest of the operating conditions are assumed to be as follows:
User's program:
Inner Boards:
Communications Units: No Controller Link Unit
Clock:
RS-232C port:
Cycle time:
Note The average processing time for a single instruction in the user's program is
assumed to be 0.625 µ s.
The cycle times are as shown in the following table.
Calculation method
Fixed
0.625 × 2000 (µs)
Negligible
0.01 × 3 + 0.005 × 2 (µs)
Minimum time
0.4 + 0.26 (ms)
0 ms
(1) + (2) + (3) + (4) + (5) + (6)
1. The cycle time can be automatically read from the PC via a Peripheral De-
vice.
2. The maximum and current cycle time are stored in AR 26 and AR 27.
3. The cycle time can vary with actual operating conditions and will not nec-
essarily agree precisely with the calculated value.
4. The RS-232C and peripheral port service time will be 0.256 ms minimum,
65.536 ms maximum.
The following table lists the execution times for CQM1H instructions. The max-
imum and minimum execution times and the conditions which cause them are
given where relevant. When "word" is referred to in the Conditions column, it
implies the content of any word except for indirectly addressed DM words.
Indirectly addressed DM words, which create longer execution times when
used, are indicated by "*DM."
2,000 instructions
(consisting of LD and OUT instructions)
Serial Communications Board and
High-speed Counter Board
None
Used
Variable (no minimum set)
Time with peripheral
device
0.8 ms
1.25 ms
0 ms
0.04 ms
0 ms
0.34 ms
0.66 ms
0 ms
3.27 ms
Section 7-3
Time without peripheral
device
0.8 ms
1.25 ms
0 ms
0.04 ms
0 ms
0 ms
0.66 ms
0 ms
3.01 ms
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