Measure Cold Junction
+ Sensor error check
Measure Channel 1
Measure Channel 2
Measure Channel N
Unit initialisation
■
DIP switches
8 DIP switches are accessible after removing the
front terminal block. Switch settings are processed at
time of power ON, and should not be changed while
the unit is powered.
Default (ex-factory) setting is all switches ON,
i.e. all 6 inputs are active and set to K-type
thermocouple, with filtering at n x 100 Hz. Be sure
to adjust the settings to your requirements before
use.
SW 1, 2 and 3 : Input type selection
Any combination of input types (different numbers of K-type/J-type
sensors) can be set.
SW
State
Input type selection
OFF
Input channel 1 is J-type
1
ON
Input channel 1 is K-type
OFF
Input channels 2 and 3 are J-type
2
ON
Input channels 2 and 3 are K-type
OFF
Input channels 4, 5 and 6 are J-type
3
ON
Input channels 4, 5 and 6 are K-type
SW 4 + 5 : Input filtering (valid for all active input channels)
Use filtering if the measured value is affected by the mains frequency or
other sources of electrical interference.
SW4 SW5 Filtering
Response
time
OFF
OFF
n x 10 Hz suppression
400 ms each input
OFF
ON
n x 50 Hz suppression
80 ms each input
ON
OFF
n x 60 Hz suppression
67 ms each input
ON
ON
n x 100 Hz suppression
40 ms each input
SW 6+7+8 : Input activation
To prevent broken wire indication for unused inputs, and to reduce the
number of input channels occupied in CIO memory, the number of
required inputs can be set by SW 6+7+8.
Input words are allocated in the PLC’s CIO area as Basic I/O Unit, i.e.
sequentially starting at the leftmost unit. See CJ1-series Operation
Manual W393 for details.
Create the I/O table in the PLC after changing the switch settings, to
register the correct number of input words in the PLC CPU. The unit is
registered as 48-point, 64-point, or 96-point input unit, depending on the
number of 16-bit CIO words it occupies.
SW6 SW7 SW8 Active inputs
Occupied input words
OFF OFF OFF Not valid, ERC indicator will be ON
ON OFF OFF 1
3 CIO words (1 used)*
OFF ON OFF 1, 2
3 CIO words (2 used)*
ON ON OFF 1, 2, 3
3 CIO words
OFF OFF ON 1, 2, 3, 4
4 CIO words
ON OFF ON 1, 2, 3, 4, 5
6 CIO words (5 used)*
OFF ON ON 1, 2, 3, 4, 5, 6
6 CIO words
ON ON ON 1, 2, 3, 4, 5, 6
6 CIO words
* In these cases, more CIO words will be occupied than required for the
active inputs. The remaining occupied CIO words will be filled with 0’s,
and cannot be used as work bits.
■
Data representation
Measured temperatures are indicated in °C. Each input value
occupies one word (16 bits) in the CIO area and is encoded as a
signed integer, with a resolution of 0.1 °C.
Examples: #0300 =
768 (dec) =
76.8 °C
#FF85 =
-123 (dec) =
-12.3 °C
Measured values are updated in CIO memory in each I/O refresh cycle.
The following values are to be interpreted as error codes:
Value Description
#7AAA
Calibration data invalid or error detected at start-up,
e.g. cold junction temperature out of range.
#7BBB
Sensor error, broken wire
#7CCC
Measured value out of range (over max. Temperature)
#8CCC
Measured value out of range (under min. Temperature)
During initialisation after power ON, data of active inputs will be #0000
until the “Not Ready’ flag turns OFF.
■
‘Not Ready’ flag
During initialisation after power-on, and in case of internal failure, a
‘Not Ready’ flag will be set in the PLC memory area A050 to A069
(Basic I/O Unit information area, refer to CJ1 Operation Manual W393
for details).
The lower bit of each unit is the Not Ready flag; the error code
indicated in the remaining bits is relevant for repair purposes only.
While this flag is ON, the temperature sensor data indicated by the
unit in the CIO area is invalid.
Address Bit
When Bit = ON
00
Unit in rack 0, slot 0 is not ready
A050
08
Unit in rack 0, slot 1 is not ready
00
Unit in rack 0, slot 2 is not ready
A051
… …
00
Unit in rack 1, slot 0 is not ready
A055
… …
00
Unit in rack 3, slot 9 is not ready
A069
08
Unit in rack 3, slot 10 is not ready
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Unit cycle time
The internal processing time for all measurements by the unit is
determined by the number of active channels and the filter type.
The cold junction compensation
measurement and one sensor error
check are executed each cycle.
The cold junction measurement
time depends on the input filter
setting, whereas the sensor error
check takes a fixed 40 ms.
Example:
If 4 inputs are active, and filtering is
set to n x 50 Hz (response time =
80 ms):
Each measurement cycle takes
(4+1) x 80 + 40 ms = 440 ms.
OMRON CORPORATION
Note: Specification subject to change without notice
Printed in The Netherlands
1634299-2A
OMRON ELECTRONICS LLC
Phone: 1-847-843-7900 or
1-800-55-OMRON
OMRON CANADA INC.
Phone: 416-286-6465
Phone: 1-514-636-6676 (French)
