Argantix XDS 100-100, User And Programming Manual

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User and Programming Manual
86 XDS Series
10.6 Programming Tips
When developing custom application code, the following guidelines should be followed if possible:
All commands should be terminated with <NL> (hex 0A) character. In "C", the \n character sequence
will result in a <NL> character. This is the message terminator.
The receive buffer of the XDS is limited to about 21 characters. Avoid sending long compound
message strings consisting of multiple commands. Commands longer than the receive buffer will
result in "-100, Syntax Error"
Successive non-query commands (e.g. VOLT 100) sent to the unit should be spaced at least 20
msec apart. This is to allow the interface of the unit to receive and transmit the command over it's
internal optically isolated serial bus to the main processor. This process takes place for both GPIB
and RS232C control so this 'command hold-off' delay period is needed regardless of which interface
is used. The same delay is not required following a query command (e.g. VOLT?) as the application
program generally waits for the response before sending the next command.
Inserting this delay does not affect real through put as the unit would not respond any faster if
commends were sent consecutively without delays in between.
Some commands take extra time to execute as they update the non-volatile memory of the unit. In
particular, the *SAV command requires 300 msec to complete. No commands should be send during
this time period.
It is good practice to check for error messages using the *ESR? or SYST:ERR? Queries. The XDS
does not generate an SRQ on the GPIB bus so programmed polling is needed to check for status or
errors.