AMETEK DLM600 Series - Manual (Page 13)

10 Addendum
4.1 Remote Shutdown Operation, DLM Functionality
(with Iso Relays)
1.1.3 Shutdown Trigger - TTLSD
• The output is inhibited with a TTL level high (5V).
• User to connect rear panel utility Digital I/O 8 pin J4 connector next to the GPIB; the pins
are J4-2, TTLSD and GND J4-5.
• A high level will disable the output converter and open the relays for the duration of that
level.
• The output voltage will be reduced to 0V in less than 50ms.
• When TTLSD level is back to low, the output will return to its previous value and the relay
will remain open, disconnecting from the load.
• GPIB SRQ is possible if the faults event register is enabled and the TTLSD is high, a
serial poll will return SRQ 49h.
LATCHED SHUTDOWN
• The relay will disconnect requiring a <*RST> instruction and then you can
reprogram the power supply. In addition, the end user could have the unit return
an SRQ and use it within the shell program to, in turn, reset the unit.
• The fault event register must be enabled by the protection enable register to
record in the fault register. The user can use it as filter and select specific events.
• Instructions:
*cls ; clears status register
*stb? ; reads register s/be “0”
sour:curr 5 ; regular instruction set current to 5A
sour:volt 25 ; regular instruction to set output voltage to 25V
outp:isol on ; regular instruction to turn on the isolation relays
stat:prot:enab 32 ; to enable bit 5 0x20 hex or 32 in decimal
*sre 2 ; bit 2 will cause a service request
At this point if the TTLSD is enabled….
serial poll
; to read SRQ
(ans) $42 ; 4 = service request and 2 = prot. Event bit
FRONT PANEL INDICATION
The output light will go off and the voltage and current displays will show 0’s.
RECOVERING FROM THE SHUTDOWN EVENT (i.e. *RST)
If the shell program resets the unit after the SRQ is acquired, then the unit is
ready to be reprogrammed.