pag. 9
MDE/C133 2561 001
MX3IPG2A
3.7 Main and spare settings
The device can store two groups of settings, named 'main' and
'spare' settings, which can be programmed through the
keyboard, a Personal Computer or a network.
The current settings are indicated on the display unit with the
text 'SETTINGS IN USE'.
The device, notwithstanding the selections made, can be
"forced" to use the SPARE settings. Such forcing can be
enabled from the network or through a continuous signal to be
sent to the digital input (IN DIG 1), previously set to implement
this function. This condition is signalled by the presence of the
characters <!> next to the selected settings; when the signal
drops, the previously selected group of settings is enabled
again, whereas the characters <!> disappear (see paragraph
6.1.3).
4. ADDITIONAL FUNCTIONS
4.1 Diagnostics
Diagnostic activities are envisaged which are automatically
carried out upon powering on the device as well as from time
to time during the running, and which provide the following
actions:
- signalling fault or failure conditions. This signal de-
energizes the diagnostic relay, turns off the green LED
(indicating running system) and lights up the red LED
(indicating system failure).
- system lock-out in the event of faults that might entail ill-
timed operation (VITAL FAULTS).
- failure code display.
The following failures are classed as NON-VITAL FAULTS:
- output relay(s) (X1 - X5) failure
- communication failure
- internal clock failure
The following failures are classed as VITAL FAULTS:
- feeder failure
- EEPROM failure
- internal or external RAM failure
- Analogue/Digital converter failure
In the presence of vital faults, the device will automatically
displays the fault code; this condition can only be reset, if the
equipment allows this condition to be reset, by enabling the
"settings change' command.
In the event of , upon starting up the equipment, an EEPROM
failure making it impossible to retrieve the information on the
selected dialogue language, the device will continue working
using Italian as the default dialogue language.
The device includes the 'Watch Dog' function.
The diagnostic activity is also aimed at signalling any condition
of "inhibited equipment"; this condition is displayed with a
dedicated code, the diagnostic relay is de-energized and the
red LED (faulty device) lights up. This condition can only be
reset by enabling the 'change settings' command.
The diagnostic menu also indicates the date when last changes
were made to the equipment.
4.2 Output circuits
The output circuits are composed of six relays, each of them
equipped with two contacts (see block diagram).
The X6 relay, normally energized, is strictly assigned to the
diagnostic function.
Each of the five relays left, if duly programmed from the
keyboard, a Personal Computer or a network, can be:
- set to perform one or more functions
- preset for:
- monostable operation: immediate return to the quiescent
position when the cause that operated it is removed.
- bistable operation (MEMOR): the tripping position is main-
tained until a reset signal comes from the front push-button,
the digital input or the serial connection.
- a minimum duration of the signal or command (t_IMP).
The output relays, except for the diagnostic relay, can all be
simultaneously set to "normally energized" (NORMAL.ON=ON)
or "normally de-energized" (NORMAL.ON=OFF): this selection
is made by acting on the settings change function.