Toshiba GR-200 Series Instruction Manual page 331

Resetting judgment and blocking commands
(iv)
ATO judgement will be stopped and ATC commands will be blocked, if the below is found in
certain circumstances and conditions:
Reset condition:
Reset condition can be described such that ATO judgement shall be removed when ATO
commands are not being generated after the ATO judgement has been generated. If it is
observed over the timer [T_ATO_Reset], ATO process shall be reset.
Blocking by current change:
It is possible to stop the ATO judgment and not to issue ATO commands, if changing
current has been observed. It can be done when Block has been set for setting [ATO-
ROCOCBlk]. The changing current will be monitored in current change detection relay
(ROCOC), which the user can characterize using setting [ROCOC_ATO].
Suppose that changing current has been observed between the latest current phasor
(IM) and the past current phasor (IN; 2 cycles before), the ROCOC relay operates, when
it has been observed for over the [ROCOC_ATO] period. Incidentally, there are three
operation characteristics and the user can select one of three characteristics using
setting [ATO-ROCOC-Chara]. The relay characteristic will be expressed with either
increment (Rise), decrement (Down), or increment/decrement (Both).
Table 2.27-1 ROCOC relay characteristics
Settings [ATO-ROCOC-Chara]
The ROCOC operating signal will be outputted continuously over [T_ATO_ROCOC]
timer.
Blocking by user PLC logic:
It is possible not to issue the ATO commands if a signal is generated at PLC
'ATO_BLOCK'. User PLC logic could generate the block signal, which can block the ATO
operation if ATO judgement is running.
Rise
Down
Both
- 312 -
Characteristics formed in ROCOC relay
I - I > Setting[ROCOC_ATO]
M N
I - I > Setting[ROCOC_ATO]
N M
|I - I | > Setting[ROCOC_ATO]
M N
6F2T0200 (0.15)
GRE200 (1,2)