Omron C200H Operation Manual page 30

Functions and Programming
Setting Method
Sampling Period
Additional Information
2-3-2 Input Signal Range Setting
Function
Setting Method
Example
20
The conversion prohibit setting is made in bits 00 to 07 of DM word m. Set the
corresponding bit to "1" to prohibit conversion for that input.
Bit 07 06 05
DM m
The "sampling period" is the amount of time between A/D conversion processing
for a given input. The sampling period for this Unit can be determined from the
following equation:
Sampling period = 4 ms + (number of enabled inputs) × 2.5 ms
The base sampling period of 4 ms excludes effects such as temperature drift.
This processing is performed every time after A/D conversion has been per-
formed for the last enabled input.
Stopping conversion for unused inputs reduces the number of enabled inputs
and the sampling period, as shown in the following table.
Number of enabled inputs
1
2
3
4
5
6
7
8
The following amount of time is required to read the conversion data to the CPU.
Min. time required = (sampling period) + (cycle time)
Max. time required = (sampling period) + (cycle time) × 2
Sets the input signal range to match the input signal being used for each input.
The input signal range setting for each input is made with two bits in DM word
m+1. Set the corresponding pair of bits to the desired value for that input.
Bit 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
DM (m + 1)
Bit
Leftmost bit Rightmost bit
0 0
0 1
1 0
1 1
This example shows how to set DM word m+1 to set the following input signal
ranges.
04 03 02 01 00
Sampling period
6.5 ms
9.0 ms
11.5 ms
14.0 ms
16.5 ms
19.0 ms
21.5 ms
24.0 ms
Input signal range p
–10 to +10 V
0 to +10 V
+1 to +5 V/+4 to +20 mA
Not used.
Section 2-3
0: Conversion enabled
1: Conversion disabled
g g