YOKOGAWA WT110 User Manual page 90

10.4 Comparator Function (optional)
CAUTION
10-8
Dual Mode
This mode allows you to combine the limit values of two relays (e.g. the upper value (Hi) and
the lower value (Lo)) to determine the contact status. The four relays will be fixed as two pairs
of ch1 & ch2 and ch3 & ch4. Setting the limit values of a pair of relays (e.g. ch1 & ch2) can
only be done at the same display function. The setting method, relay operation, etc. are the same
as in the single mode, and when the measured/computed/integrated/analysis values exceed the
preset limits, the contact status will become NO.
The following shows an example.
When the current value exceeds 1A, but is less then 3A: GO will be ditermined
and the circuit becomes closed.
When the current value lies below 1A, or exceeds3A:NO-GO will be determined
and the circuit becomes open.
Current
Upper limit(Hi)
3A
1A Lower limit(Lo)
NO-GO determination area
Current
Upper limit(Hi)
3A
GO determination area
1A Lower limit(Lo)
Current
NO-GO determination area
Upper limit(Hi)
3A
1A Lower limit(Lo)
Note
• In the dual mode, the combinations ch1&ch2, and ch3&ch4 are fixed. The combinations ch1&ch3 and
ch2&ch4 are not possible.
• Within a pair you can set either channel as upper or lower limit.
Make sure not to greatly vary the input signal when using the comparator
function. Depending on the input signal used for determination, the
instrument may display error codes (i.e. overrange) and this will change the
output relays as follows. When using the output relay as a control signal,
make sure to match these control signals with other equipments to
eliminate erroneuous control.
Displayed error
oL (over range)
oF (over flow)
dEGEr (phase angle error)
PFErr (power factor error)
ErrLo (frequency error)
ErrHi (frequency error)
FrqErr (frequency error in case of harmonic analysis)
—— (error when no data are present)
Below lower limit
⇒ open circuit
Limit of ch1 is set to 3A
Limit of ch2 is set to 1A
Time
Exceeding lower
limit, below upper
⇒ closed circuit
Limit of ch1 is set to 3A
Limit of ch2 is set to 1A
Time
Exceeding upper
limit
⇒ open circuit
Limit of ch1 is set to 3A
Limit of ch2 is set to 1A
Time
NC
COM
NO
24V
NC
COM
NO
NC
COM
NO
24V
NC
COM
NO
NC
COM
NO
24V
NC
COM
NO
Relay status
The NC contact is closed.
The NC contact is closed.
The NC contact is closed.
The NC contact is closed.
The NC contact is closed.
The NO contact is closed for this
case only.
The NC contact is closed.
The NC contact is closed.
IM 253401-01E
ch 1
ch 2
ch 1
ch 2
ch 1
ch 2