72-92 PN-0908073 Rev. 11
PS 164-2
THE ART OF WELDING
◊ The synoptic card (21700634)
The synoptic card interfaces with the following pe-
ripheral units:
• Remote control pendant.
• Programming keyboard.
• Synoptic on the front panel.
• Display on the front panel.
• Printer.
• Memo card.
It is controlled by the sequencer card via an I²C
link.
The interface with the remote control pendant is
made by constantly checking the state of the but-
tons with a line and column system. By successively
activating the different lines and testing the columns
it is determined which buttons or switches have been
activated.
The stop command BT 7 is linked directly to the se-
quencer card, without passing via the I²C bus. The
emergency stop button BT 2 on the remote control
pendant is linked also to the power on/off switch.
This ensures the safety of the users in the case of a
cycle stop or an emergency stop.
The programming keyboard is based on the same
principle. Only the key switch "Modifi cation author-
ised or not" has a direct link.
The interface with the synoptic indicators is made
by multiplexing. The indicators are not permanently
supplied with power, but instead by a signal (mul-
tiplexing supply) which has a frequency of several
hundred Hertz.
The contrast and brightness of the screen is control-
led by the synoptic card. The procedure for their ad-
justment is given in paragraph 6.1.1.
The memo cards used with the PS 164-2 are compat-
ible with the databus I²C. The presence of a signal
"Memo card engaged", resulting from a contact in the
connector, authorises all other connections, including
the 5 V power supply. The card is thus protected from
overloads during its insertion and its removal.
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