CAEN
Electronic Instrumentation
UM2679 – A1536 AG536 Family Power Supply Boards
11
OVV
(channel in OVERVOLTAGE condition)
UNV
(channel in UNDERVOLTAGE condition)5
EXTTRIP
(channel OFF due to external TRIP line signal)6
INTTRIP
(channel OFF due to internal OVERCURRENT condition)
EXT_DIS
(channel disabled by board INTERLOCK protection)
Moreover it is possible to monitor board temperature and to check board status; the following messages may be
returned by the SYSTEM when monitoring the board status:
UNDER_TEMP (board temperature < 5°C )
OVER_TEMP (board temperature > 65°C)
Output Enable
In order to enable the HV output channels, first of all it is necessary that pin 9 and 10 on the Radial 52pin output
connector are short circuited (see p.7); if the board features SHV connectors, skip this step.
Then the enable procedure is completed in one of the following ways:
Boards with LEMO interlock connectors
terminating the PASSIVE INTERLOCK [P] (see External connections) connector on 50 Ohm.
supplying the SIGNAL INTERLOCK [S] (see External connections) connector with a +5 V (3-4mA) signal.
Boards with AMP interlock connectors
Short circuit pin 3 and 4 [the lower ones]. Leave contact open between pin 1 (+) and 2 (-) [upper ones]
Apply +5 V (3-4mA) differential signal between pin 1 (+) and 2 (-); pin 1 is the upper one. Leave contact open
between pin 3 and 4.
The INTERLOCK LED (red) is turned off as one of the actions above is performed.
When the channels are disabled the voltage outputs drop to zero at the maximum rate available; when the output
disable cause is removed (see above), the channels remain OFF until the User turns them ON via software.
Grounding specifications
The A1536 channels share a common floating return (RTN), insulated from the crate ground (AGND/EARTH). This
feature allows on-detector grounding, thus avoiding loops which may increase noise level. RTN and AGND may be
coupled in several ways, according to environment requirements. Examples refer to 32 channel version (A1536).
Safety Earth connection
The connection of shield and return to Earth is fundamental for User safety. The connection must always be at the
level of detector or power supply system. Return and Shield connections, even if not present or performed
incorrectly, due to protection circuits implemented on the A1536 are bound to Earth; in this case the voltage
difference between return and Earth (System), shield and Earth is limited to approximately 50V. Please note that
this is a status of emergency-protection, not a working one. The Connector Configurator allows to optimize the
5
UNV is also reported when Hvmax limit is reached, it is up to the User to verify that VMON value does not exceed HVMAX.
6
EXTTRIP and INTTRIP parameters are expressed in Hexadecimal format
