KEPCO TMA 4882-27 - Manual (Page 27)

TMA 4882-27 021910
3-1
SECTION 3 - OPERATION
3.1 LOCAL OPERATION
There is no local operation of the TMA 4882-27 controller; however, the controller provides three
auxiliary functions (emergency shutdown, discrete fault, and +5V output, PAR. 3.2) to the user,
in addition to the remote programming capability described in PAR’s 3.3 through 3.7.
3.2 AUXILIARY SIGNALS
The AUX SIGNALS connector (see Table 2-4 and Figure 2-2) at the rear panel provides the fol-
lowing auxiliary functions: emergency output shutdown, discrete fault, and +5V output.
3.2.1 EMERGENCY OUTPUT SHUTDOWN
The emergency output shutdown function allows the user to reset all the power modules con-
nected to the Control Bus with a single discrete signal. A user-initiated emergency shutdown
activates the non-maskable interrupt of the microsystem, forcing the microsystem to send a
reset to all power modules connected to the Control Bus. The NON-ISOLATED EMERGENCY
SHUT-DOWN INPUT accepts a TTL input signal to initiate shutdown; this signal is referred to
signal common. The ISOLATED EMERGENCY SHUT-DOWN INPUT requires a 2-wire isolated
signal and return path.
3.2.2 DISCRETE FAULT LINE
When operating in Remote mode, the DISCRETE FAULT LINE function provides a discrete con-
troller fault indication by means of an internal relay; this function is inactive in Local mode. The
DISCRETE FAULT LINE relay contacts are open (open circuit between DISCRETE FAULT
LINE PIN 1 and PIN 2) if the internal microsystem is functioning normally by monitoring a pulse
generated in the timer interrupt routine. If the microsystem is not functioning normally, or a cata-
strophic condition appears on one of the power modules, the contacts will close. The contacts
reopen when the catastrophic condition disappears and either the error buffer has been read (if
the Command Language is CIIL) or when the Device Dependent Error from the Event Status
Register has been read (if the Command Language is SCPI).
It is possible to use the DISCRETE FAULT LINE to reset all units connected to the IEEE 1118
Control Bus by connecting pin 10 to pin 12 and pin 11 to pin 14 of the AUX SIGNALS connector.
In this case when the DISCRETE FAULT LINE relay contacts close, a NON-ISOLATED EMER-
GENCY SHUTDOWN signal is also produced, causing the *RST command to be sent to all
units on the Control Bus (see PAR. 3.2.1). A prewired STATUS MONITOR RESET connector
(see Table 1-2) is available as an accessory to easily implement this feature.
3.2.3 +5V OUTPUT
The +5V output is an auxiliary +5V source supplied through a 390 ohm resistor which can be
used to power user-supplied external TTL circuits.
3.3 REMOTE OPERATION
Kepco TMA 4882-27 Power Module Controller controls one or more Kepco power supplies
using either SCPI (Standard Commands for Programmable Instruments) or CIIL (Control Inter-
face Intermediate Language) commands. SCPI and CIIL provide a common language used in
an automatic test system. These commands are received via either the IEEE 488 standard com-
munication bus (General Purpose Interface Bus, GPIB), or the RS232C communication bus.