Register Bit Descriptions Chapter 4
GPIB-1014 User Manual 4-30 © National Instruments Corporation
Table 4-5. Auxiliary Commands: Detail Description (continued)
Command Code
(COM4-COM0)
4 3 2 1 0 Description
0 0 0 1 1 Finish Handshake (FH)
The Finish Handshake command finishes a GPIB Handshake that
was stopped because of a Holdoff on RFD or DAC.
0 0 1 0 0 Trigger
Note: Trigger cannot be used with the GPIB-1014.
The Trigger command generates a high pulse on the TRIG pin
(T/R3 pin when TRM1=0) of the TLC. The Trigger command
performs the same function as if the DET (Device Trigger) bit
(ISR1[5]r) were set. (The DET bit is not set by issuing the
Trigger command.)
0 0 1 0 1 Return to Local (rtl)
0 1 1 0 1 Return to Local (rtl)
The two Return to Local commands implement the rtl message as
defined by IEEE 488. When COM3 is zero, the message is
generated in the form of a pulse. When COM3 is one, the rtl
command is set in the standard manner.
0 0 1 1 0 Send EOI (SEOI)
The Send EOI command causes the GPIB End Or Identify (EOI)
line to go true with the next byte transmitted. The EOI line is then
cleared upon completion of the Handshake for that byte. The TLC
recognizes the Send EOI command only if TA=1 (that is, the TLC
is addressed as the GPIB Talker).
0 0 1 1 1 Non-Valid Secondary Command or Address
The Non-Valid command releases the GPIB DAC message held
off by the Address Pass Through (APT). The TLC is permitted to
operate as if an Other Secondary Address (OSA) message has been
received.
0 1 1 1 1 Valid Secondary Command or Address
The Valid command releases the GPIB DAC message held off by
APT and allows the TLC to function as if a My Secondary Address
(MSA) message had been received. The DAC message is released
at the time of Command Pass Through (CPT). DAC is also
released if DCAS or DTAS is in Holdoff state.
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