Display and Loop Card compatibility
The Syncro multi-loop control panel has been
approved to EN54-2 / EN54-4 by BSI since 2004.
As part of the revisions made to the control
panel for this certification process, there
was an amendment to the panel display card
hardware. This revision included the addition
of a memory “write enable” switch
to the display card, plus a different fault-warning
buzzer with a higher output volume.
In addition, there were some revisions to
the panel firmware, to monitor the write enable
switch position and to monitor all microprocessors
in the control panel for the EN54-2 “system
fault” compliance. Finally, there was
also a revision to the menu structure.
The older Syncro display cards had the part
reference “S550” and would have
firmware revisions V1.00 – V4.61 installed.
Following certification, the panel display
cards have the part reference S550ENH (Hochiki),
S550ENA (Apollo) and S550ENV (Argus Vega).
These display cards would have V5.00 or higher
If there is ever a requirement to
replace a display card on a non-certified
panel with firmware version V4.6 (or older),
then this must be replaced with a S550 display
If the S550 is replaced with an S550ENA/H/V
display card the panel will report a “System
This System Fault is result of the loop cards
not supporting a memory test facility required
under EN54-2. Because the loop card fails
to respond to the memory check command, the
display assumes that there is a failure. The
only way to resolve this failure is to either
use the S550 display card, or to replace the
loop cards with newer version hardware.
To summarise -
S550 display card –
Version 1.00 though to V4.61 firmware –
replace with S550 only.
S550ENH / S550ENA / S550ENV display
card – Version 5.00 or higher
– replace with same display part code
NOTE: The part reference of the display card
is given on the bar code label, along with
the batch number and item number of the batch.
This should be used to confirm the part reference
when replacing boards.