C500MP102EV3 Omron, C500MP102EV3 Datasheet - Page 151

• Manufacturer Part Number: C500MP102EV3
• Description: K-TYPE PC MEMORY RACK
• Manufacturer: Omron

Specifications of C500MP102EV3

• Leaded Process Compatible: No
• Peak Reflow Compatible (260 C): No
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Cycle Time
140
Watchdog Timer and Long
Cycle Times
1
2
3
4
Overseeing
Peripheral Device
servicing
Instruction
Input refreshing
Output refreshing
execution
1, 2, 3...
Watchdog timer set and program memory
and I/O bus checked.
Commands from Program Devices and
Interface Units processed.
Instructions executed.
Reading data input from input terminals
and writing the results of instruction
execution to output terminals.
The first three operations immediately after power application are performed
once each time the PC is turned on. The then on the operations shown
above are performed in cyclic fashion, with each cycle forming one cycle.
The cycle time is the time that is required for the CPU to complete one of
these cycles. This cycle includes four types of operation.
1.
2.
3.
4.
Cycle time = Overseeing time + Input/output refreshing + Peripheral
Device servicing time + Instruction execution time
The cycle time can be obtained by adding the four cycle time components
identified above. An adequately short cycle time is important to ensure effi-
cient, error-free operation.
Within the PC, the watchdog timer measures the cycle time and compares it
to a set value. If the cycle time exceeds the set value of the watchdog timer,
an error is generated and the CPU stops.
Even if the cycle time does not exceed the set value of the watchdog timer, a
long cycle time can adversely affect the accuracy of system operations as
shown in the following table.
10 or greater
100 or greater
Between
100 and 130
130 or greater
Cycle time (ms)
Overseeing
Input/Output refreshing
Peripheral Device servicing
Instruction execution
TIMH(15) becomes inaccurate.
0.1-second clock pulse generator SR 1900 may
malfunction.
ALARM indicator on the CPU lights and SR 1809 turns ON.
ERROR indicator on the CPU lights and the system halts.
Possible adverse affects
1.6 ms (Fixed)
T = ( 1 + 3 + 4 ) x 0.05.
T <= 1, execution time = 1 ms.
T > 1, round off in units of 0.5 ms
(e.g.,1.65 ms rounds to 1.5 ms)
No peripherals connected = 0 ms.
Total of execution time for each instruction.
Varies with program size, the instructions
used, and execution conditions. Refer to
6-4 Instruction Execution Times for details.
0.51 ms + 0.03 ms times N where N =
number of input and output words – 2.
Section 6-2