Boonton 9240 RF Voltmeter - Manual (Page 51)

Boonton 9240 Series RF Voltmeter
5. Remote Operation
5.1 GPIB Configuration
The 9240 GPIB interface is configured using the Menu > SETUP > IEEE menu. The primary listen/talk address (MLTA) can
be set to any value from 1 to 30 inclusive. The value assigned must be unique to each GPIB device. Secondary address is
not implemented.
To inform the instrument that a message has been completed, the bus controller must end all messages with a terminating
character and/or EOI control signal. The Model 9240 can be programmed for several combinations of terminating characters
as required by the controller employed. Selection of terminating characters is accomplished via the Menu > SETUP > IEEE
menu. There the instrument can be programmed for individual end of string characters in both listener and talker modes as
well as independently enabling the end or initiate control signal.
5.2 RS-232 Configuration
RS-232 interface is also available on the Model 9240. The command set and data transfer protocol are nearly identical to
those for IEEE. The Menu > SETUP > RS232 commands are used to configure the RS-232 interface to comply with the
terminal in use. Setting the end-of-string character and SRQ Mask is accomplished by using the EOS Talker/Listener and
SRQ Mask commands respectively.
Entering the Remote Mode. The Model 9240 enters the remote mode when the ASCII "SI" character (hexadecimal
0F/CTRL O) is received. In the remote state, the front panel keyboard is disabled, except for the
Note The instrument must be placed in the remote state for it to respond to data messages. It is not possible to
store data in the local state for execution in the remote state.
Talk Operations. The Model 9240 can be requested to talk in two ways. The "??" mnemonic is available for requesting data
via the RS-232 port. Immediately after receiving this mnemonic, the instrument responds by transmitting data based on the
current talk mode. For example, the following interactive sequence causes the Model 9240 to transmit the measurement with
the associated units (4230 IEEE Emulation mode):
Terminal Sends Model 9240 Response
O (CTRL O/hexadecimal 0F) REM displayed on bottom line, indicating remote operation.
DB TM1 ?? Set measurement to dBm, set the talk mode to 1 (talk measurement with units).
Data returned: “0,-3.00 dBm” - indicating no error at -3 dBm.
Note means transmit end-of-string as defined via the Menu > SETUP > RS232 > EOS LSTN
parameter (typically CR).
Remote Operation
5-1