Instruction manual

6.4.6 Special Notes For the Controller Software Writer
This section will provide some valuable hints to the controller software program
writer for interfacing this Programmable Unit, through the communication interface.
1). Normal communication is in ASCII. The unit will accept both the lower case and
upper case characters.
2). All commands for the units are in the IEEE-488.2 and SCPI format.
3). All mandatory commands for IEEE-488.2 are implemented in the unit.
4). Also the command has to be sent with proper terminator (The Program Mes-
sage Terminator is either = 0AH (NEWLINE) OR EOI message OR both of the
above). Else the command processing will not start.
5). For the responses of query commands, the Response Message Terminator or
EOS character will be OAH (New Line) character.
6). For all commands <AARD> means Arbitrary ASCII Response Data and
<NR.DATA> means Numeric Data.
7). For wrong commands, the command error bit will be set & an error message is
put into Error Queue.
8). Unit will go to remote mode for all valid commands. Queries will not force the unit
into remote mode.
9). The GPIB ‘GTL’ command will send the unit into Local mode.
10). IEEE-488 device clear commands ‘SDC’ & ‘DCL’ will generate a communication
soft reset to the unit. Present communication buffer will be flashed out. But, the
unit will maintain the last settings.
11). When the unit has received MLA (My Listen Address) with REN line true, it will go
to remote mode as per the RL2 function requirements.
12). The unit provides complete SRQ function. Refer section 5.10 for details. When
the controller polls the SRQ response byte, it is found in case of some control-
lers that this response byte gets latched in the controllers data in buffer causing
an extra character while reading the next message through GPIB. So, it is advis-
able to give a dummy listen to the controller GPIB controller chip with sufficient
time-out to flash out such character if pending any.
35