Rohde & Schwarz SMC100A, Operating Manual

Page: 187 / 363

Remote Control Basics
R&S
®
SMC100A
170 Operating Manual 1411.4060.32 ─ 04
nected via an external USB/serial-adapter (see recommended extras, data sheet) and a
serial crossover (null modem) cable. A USB connection requires the VISA library to be
installed on the controller. VISA will detect and configure the R&S SMC automatically
when the USB connection is established.
Serial address
The used serial address string is:
ASRL[0-9][::INSTR]
where
ASRL[0-9]
determines the number of the COM port on the controller side, that
has to be used for the serial connection.
Access via a bluetooth device requires the entry of the bluetooth pin in addition (see
​
chapter 5.2.3.13, "Security" , on page 91).
To enable an error-free and correct data transmission, the parameters of the generator
and the controller must have the same setting. The serial interface is preset for a baud
rate 115200, no parity and one stop bit. The parameters can be manually changed in
"Remote Channel Settings" dialog (see
​
chapter 5.2.3.11, "Remote Channel Set-
tings" , on page 88).
6.1.6 GPIB Interface (IEC/IEEE Bus Interface)
To be able to control the instrument via the GPIB bus, the instrument and the controller
must be linked by a GPIB bus cable. A GPIB bus card, the card drivers and the program
libraries for the programming language used must be provided in the controller. The con-
troller must address the instrument with the GPIB bus address (see
​
chapter 6.1.6.2,
"GPIB Instrument Address" , on page 171).
Characteristics
The GPIB interface is described by the following characteristics:
●
Up to 15 instruments can be connected
●
The total cable length is restricted to a maximum of 15 m; the cable length between
two instruments should not exceed 2m.
●
A wired "OR"-connection is used if several instruments are connected in parallel,
since the slowest instrument determines the speed.
Any connected IEC bus cable must be terminated by an instrument or controller.
6.1.6.1 GPIB Interface Messages
Interface messages are transmitted to the instrument on the data lines, with the attention
line (ATN) being active (LOW). They are used for communication between the controller
and the instrument and can only be sent by a computer which has the function of a GPIB
bus controller. GPIB interface messages can be further subdivided into:
Remote Control Interfaces and Protocols