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Table 3-4. Model 485 Interface Function Codes
3.4 GENERAL BUS COMMAND PROGRAMMING
Code Interface Function
SHI
AMI
T5
L4
SRI
RL2
PRO
DC1
DTI
CO
El
TEG
LEO
Source Handshake Capability
Acceptor Handshake Capability
Talker (Basic Talker, Serial Poll, Talk Only
Mode, Unaddressed To Talk On LAG)
Listener (Basic Listener, Unaddressed To Listen
On TAG)
Service Request Capability
No Local Lockout Capability
No Parallel Poll Capbility
Device Clear Capability
Device Trigger Capability
No Controller Capability
Open Collector Bus Drivers
No Extended Talker Capabilities
No Extended Listener Capabilities
Table 3-5. IEEE Command Groups
HANDSHAKE COMMAND GROUP
DAC = DATA ACCEPTED
RFD = READY FOR DATA
DAV=DATA VALID
UNIVERSAL COMMAND GROUP
ATN = ATTENTION
DCL= DEVICE CLEAR
IFC = INTERFACE CLEAR
LLO= LOCAL LOCKOUT
REN = REMOTE ENABLE
SPD = SERIAL POLL DISABLE
SPE = SERIAL POLL ENABLE
ADDRESS COMMAND GROUP
LISTEN:
LAG = LISTEN ADDRESS GROUP
MLA = MY LISTEN ADDRESS
UNL = UNLISTEN
TALK:
TAG = TALK ADDRESS GROUP
mta=my talk address
UNT = UNTALK
OTA = OTHER TALK ADDRESS
ADDRESSED COMMAND GROUP
ACG = ADDRESSED COMMAND GROUP
GET = GROUP EXECUTE TRIGGER
GTL = GO TO LOCAL
SDC = SELECTIVE DEVICE CLEAR
STATUS COMMAND GROUP
RQS = REOUEST SERVICE
SRQ= SERIAL POLL REQUEST
STB = STATUS BYTE
EOI = END
General bus commands are those commands which have the
same general meaning regardless of instrument configura
tion. These commands are grouped into two categories:
1. Addressed Commands. These commands require that the
primary address of the instrument agrees with the primary
address in the controller's programming language.
2. Unaddressed Commands. No primary address is required
for these commands. All devices equipment to implement
these commands will do so simultaneously when the com
mand is sent.
Table 3-6. General Bus Command
Command
Addressing
Required 7
HP-85 BASIC
Statement
REN
Yes
REMOTE 722
IFC
No
ABORTIO 7
GTL
Yes
LOCAL 722
DCL
No
CLEAR 7
SDC
Yes
CLEAR 722
GET*
Yes
TRIGGER 722
GET*
No
TRIGGER 7
*GET may be sent with or without addressing.
General bus commands are summarized in Table 3-6, which
also lists the HP-85 BASIC statement that sends each com
mand. Each addressed command statement assumes a
primary address of 22.
NOTE
The Model 485 must be set for a primary ad
dress of 22 to work with addressed command
examples.
3.4.1 REN (Remote Enable)
The remote enable command is sent to the Model 485 by the
controller to set it up for remote operation. Generally, this
should be done before attempting to program the instrument
over the bus. The Model 485 will indicate that it is in the
remote mode by displaying the RMT annunciator.
To place the Model 485 in the remote mode, the controller
must perform the following steps:
1. Set the REN line low.
2. Address the Model 485 to listen.
NOTE
Setting REN true without addressing will not
cause the
RMT annunciator to turn
on;
however, once REN is true, the RMT annun
ciator will turn on the next time an addressed
command is received.
3-6
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