95x Series Operating Manual - May 17, 2022
Page
125
of
155
On the GPIB interface the user must take some action to receive the response from the 95x (i.e., a READ bus
operation). If a read operation is performed when there is no data to be transmitted, then a blank data is
transmitted (i.e., a single space character followed by <CR><LF>).
If another set of commands is decoded containing a query command prior to the 95x fully transmitting a prior
response, then the new response is not provided, and an error is raised.
The following types of responses are given-
•
<BOOL>.
This is a
single character ‘0’ indicating the false condition or ‘1’ indicating the true condition.
This is always 1 character in length.
•
<STRING>
. This is one or more printable ASCII characters. This has a variable number of characters in
length and may be of no length.
•
<NR1>.
This is one or more decimal characters defining a decimal numeric value. If the polarity is positive
then no polarity character is included, otherwise the data starts with the minus character. This has a
variable number of characters in length.
•
<NR3>.
This is always 12 characters in length, and is of the following format (in the order shown)-
o
A single polarity character ( or -).
o
Six decimal characters with a decimal point character contained within them (i.e., a total of seven
characters) indicating the mantissa value.
o
The single ‘E’ (always uppercase) character.
o
A single polarity character ( or -) indicating the polarity of the exponent.
o
Two decimal digit characters indicating the value of the exponent. For clarity in engineering use
the exponent is always divisible by 3.
DELAYS AND TIMEOUTS
The user does not need to perform any delays between sets of commands, or between a set of commands
containing query commands and reading the response. The 95x automatically handshakes the commands as
needed. The only exception to this is following application of power to the 95x in which case a minimum delay of 3
seconds is required prior to operation of the interfaces.
The maximum length of time for which the 95x will
“hold
-
off” a set of commands (
e.g., waiting for a previous set of
commands to be decoded) is 100ms.
For all interfaces, responses to query commands are generally transmitted within a very short period of time,
however in some circumstances there may be some delay enforced by the 95x. The user should use a timeout of
no less than 100ms for responses.
MULTIPLE INTERFACE OPERATION
Generally, operation of the 95x via multiple interfaces is not recommended but is possible. The 95x will decode
sets of commands in the order in which they were terminated (each interface has separate receive and transmit
buffers). Any query responses will only be transmitted via the interface from which the query command
originated.
FRONT PANEL OPERATION WHILE USING INTERFACES
It is possible to inter-mix front panel and interface operation of the 95x however the user should be aware of the
following-
