RKC INSTRUMENT Z-TIO-G, Инструкция по эксплуатации

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9. COMMUNICATION DATA DESCRIPTION
IMS01T28-E4
9-21
LBA deadband
RKC communication
identifier N1
Modbus
register address ch1: 008AH (138)
ch2: 008BH (139)
Control loop break alarm (LBA) deadband gives a neutral zone to prevent the Control loop break alarm
(LBA) from malfunctioning caused by disturbance.
Attribute:
R/W
Digits:
7 digits
Number of data:
2 (Data of each channel)
Data range:
0 (0.0, 0.00) to Input span
(Varies with the setting of the decimal point position.
However, even if "3: Three decimal places" is set, the maximum settable decimal
places are 2.)
Related parameters:
Control loop break alarm (LBA) time (P. 9-20), Event 4 type (P. 9-52)
Factory set value:
0.00
Function:
The LBA may malfunction due to external disturbance from outside even when the
control does not have any problem. To prevent malfunctioning due to external
disturbance, LBA deadband (LBD) sets a neutral zone in which LBA is not
activated.
When the Measured value (PV) is within the LBD area, LBA will not be activated.
If the LBD setting is not correct, the LBA will not work correctly.
LBD differential gap
Alarm area Alarm area
Non-alarm area
A B
Set value (SV) LBD set value
Low High
LBD differential gap: RTD input: 0.8

C
Voltage input: 0.8 % of input span
If the LBA function detects an error occurring in the control loop, but cannot specify the location,
a check of the control loop in order. The LBA function does not detect a location which causes
alarm status. If LBA alarm is ON, check each device or wiring of the control loop.
When AT function is activated, the controller is in STOP mode, the LBA time is set to 0 or the
LBA function is not assigned to Event 4, the LBA function is not activated.
If the LBA setting time does not match the controlled object requirements, the LBA setting time
should be lengthened. If setting time is not correct, the LBA will malfunction by turning on or off
at inappropriate time or not turning on at all.
While the LBA is ON (under alarm status), the following conditions cancel the alarm status and
LBA will be OFF.

The Measured value (PV) rises beyond (or falls below) the LBA determination range within the
LBA time.

The Measured value (PV) enters within the LBA deadband.
A: During temperature rise: Alarm area
During temperature fall: Non-alarm area
B: During temperature rise: Non-alarm area
During temperature fall: Alarm area