ABB RET650 Technical Manual page 278

Section 12
Control
272
Local panel switch
The local panel switch is a switch that defines the operator place selection. The switch
connected to this function can have three positions remote/local/off. The positions are
here defined so that remote means that operation is allowed from station/remote level
and local from the IED level. The local/remote switch is also on the control/protection
IED itself, which means that the position of the switch and its validity information are
connected internally, and not via I/O boards. When the switch is mounted separately
from the IED the signals are connected to the function via I/O boards.
When the local panel switch (or LHMI selection, depending on the set source to select
this) is in Off position, all commands from remote and local level will be ignored. If
the position for the local/remote switch is not valid the PSTO output will always be set
to faulty state (3), which means no possibility to operate.
To adapt the signals from the local HMI or from an external local/remote switch, the
function blocks LOCREM and LOCREMCTRL are needed and connected to
QCBAY.
Permitted Source To Operate (PSTO)
The actual state of the operator place is presented by the value of the Permitted Source
To Operate, PSTO signal. The PSTO value is evaluated from the local/remote switch
position according to table 198. In addition, there is one setting parameter that affects
the value of the PSTO signal. If the parameter AllPSTOValid is set and LR-switch
position is in Local or Remote state, the PSTO value is set to 5 (all), that is, it is
permitted to operate from both local and remote level without any priority. When the
external panel switch is in Off position the PSTO value shows the actual state of
switch that is, 0. In this case it is not possible to control anything.
Table 198: PSTO values for different Local panel switch positions
Local panel switch PSTO value
positions
0 = Off 0
1 = Local 1
1 = Local 5
2 = Remote 2
2 = Remote 5
3 = Faulty 3
Blockings
The blocking states for position indications and commands are intended to provide the
possibility for the user to make common blockings for the functions configured within
a complete bay.
The blocking facilities provided by the bay control function are the following:
AllPSTOValid Possible locations that shall be able to
(setting parameter) operate
-- Not possible to operate
Priority Local Panel
No priority Local or Remote level without any
priority
Priority Remote level
No priority Local or Remote level without any
priority
-- Not possible to operate
1MRK 504 135-UEN A
Technical manual