84 GC250 Technical Manual
EAAM057608EN
You needn't use all three inputs. For example, you can use a single input to force
AUTO
status: when the input is active the controller is always in
AUTO
mode, and
when it is deactivated, the controller remains in
AUTO
mode, but you can use the
buttons to change-over to
MAN
OFF/RESET
.
If only one input is used to force OFF/RESET mode, the controller acts
differently: when the input is active, the controller is always in OFF/RESET
mode, and when the input goes back on standby, the controller goes back to
the mode it was in prior to input activation.
Sending Modbus commands through USB port. The command are only managed if
none of the above described inputs is active. Parameters can be password protected
(P.0004, refer to par. 8.5.1) which has to be sent before every command. To send the
command to change mode, it is necessary to write in sequence (within 5 seconds):
▪
HOLDING REGISTER 101: write the password configured with the parameter
P.0004.
▪
HOLDING REGISTER 102: write the value:
▪
“1” to require mode
OFF/RESET
.
▪
“2” to require mode
MAN
.
▪
“3” to require mode
AUTO
.
To enable the
TEST
mode requires the controller being first set to
AUTO
w/o any automatic
start request (refer to the engine sequence description). All possible
TEST
.
function
activation modes are described below .
TEST
mode is indicated by means of a flashing
spy
AUTO
on the panel (50% on - 50% off). You can shift to
TEST
mode as follows:
By properly configuring the parameters:
▪
P.0418: Test enable days.
▪
P.0419: Test start time.
▪
P.0420: Test duration.
These parameters allow for weekly programming of the time intervals for
TEST
mode
engine start (to keep it efficient). In this case, the passage to
TEST
is automatic in the
scheduled days and hour. The controller returns to
AUTO
when the
TEST
time
interval ends.
From a PC connected with a USB port (with protocol Modbus RTU). The controller
shifts to
TEST
after receiving the command, then, returns to
AUTO
after
receiving the opposite command or when it detects an interrupted serial connection
(60 seconds w/o messages). Parameters can be password protected (P.0004, refer
to par. 8.5.1), which has to be sent before any command, and can be disabled through
a digital input (DIF.2706). To send the command, it is necessary to write in sequence
(within 5 seconds):
▪
HOLDING REGISTER 101: write the password configured with the parameter
P.0004.
▪
HOLDING REGISTER 102: write the value:
▪
“12” to require
TEST
.
mode.
▪
“21” to go back to
AUTO
.
mode.
When a digital inpu
t, properly set with code 2031 “Test mode request” is activated, the
controller shifts to
TEST
and returns to
AUTO
when the same input is
deactivated.
