5
Fläkt Woods
8822 GB 2011.09
Speci
fi
cations are subject to alteration without notice
Installation & maintenance
Control equipment
Activation of the RS232 control line DTR
The TC35 Terminal can be switched on in the same
way as via IGT_IN by activating the RS232 control
line DTR (high signal).
Note
The TC35 Terminal is switched on immediately
using the recommended plug in power supply unit
(see the above explanation on startup).
Switching off / resetting the Terminal
The Terminal can be switched off in two different
ways:
Using a software command by means of an AT
command.
A software shutdown via an AT command is
always advisable for a controlled shut down of the
TC35 Terminal. In this case, the GSM module signs
off before the watchdog condition results in the
speci
fi
c switching off of the supply voltages.
Activation of the PD_IN reset signal on the power
supply connection.
The POWERDOWN line on the GSM module is
connected to the watchdog input pin of the power
supply ASIC, which can only be switched off by
changing the watchdog condition. To do this, the
PD_IN Terminal reset line is active (high) for at
least 3.5s. This results in immediate, ”hard” discon-
nection, with the TC35 Terminal unable to sign off
correctly from the base station in the STANDBY
and TALK operating states .
In the case of this hardware shutdown, the software
is no longer able to respond before the voltage is
switched off. This corresponds to a direct, unan-
nounced disconnection of the operating voltage. In
the application you can switch off or reset the mo-
dule without interrupting the input voltage supply
Operating states / LED
The LEDs display the following operating states of
the Terminal.
Note:
Usually, the network search takes only a few se-
conds till the Terminal is registered. If the
fl
ashing
continues, this means that no SIM card is inserted,
no PIN number is entered or no GSM network is
available
POWER DOWN
Once the operating voltage is applied (+ and GND),
the TC35 Terminal is in the POWER DOWN state.
The operating voltage for the GSM module is
disconnected (the switching regulator is off). In
other words, the software of the GSM module is not
active.
A transition to the POWER DOWN state always
occurs in the following circumstances:
• When the Terminal (module) is shut down by
means of AT commands (e.g. sleep mode).
• When the external reset line is active.
Network search (no SIM card, no PIN number, no
GSM network)
In the network search state, the TC35 Terminal sear-
ches for a GSM network. All the components in the
GSM Terminal (module) that are not required are
shut down in several stages by the energy-saving
software.
This state is reached:
• From the POWER DOWN state: by an active
ignition (on) signal at the power supply
connection or
• From the TALK or STANDBY state: when the
network is lost (out of range)
