Remote Control
R&S
®
CMW500
126
User Manual 1173.9463.02 ─ 02
Examples for channel-dependent registers
The Event Status Register (ESR) is similar to the EVENt part of an SCPI register; it
indicates instrument events. This register is channel dependent and cleared upon reading
it.
The Event Status Enable (ESE) register can be programmed individually for different
remote channels. The contents of the status byte (STB) and the conditions for the R&S
CMW500 to initiate a service request (SRQ) are also channel-specific.
6.2 Messages
The messages transferred between the controller and the R&S CMW500 can be either
interface messages or device messages.
The general structure of the device messages is defined by the SCPI standard. For spe-
cific features of the R&S CMW500 command set refer to section
6.2.1 VXI-11 Interface Messages
The VXI-11 protocol allows the instrument to be controlled in a Local Area Network. For
a short introduction and a list of interface functions refer to
.
6.2.2 GPIB Bus Interface Messages
GPIB interface messages are transferred on the data lines of the GPIB bus, the ATN
control line being active. They are used for communication between controller and instru-
ment 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:
●
Universal commands: act on all devices connected to the GPIB bus without previous
addressing
●
Addressed commands: only act on devices previously addressed as listeners
The interface messages relevant to the instrument are listed in section
.
6.2.3 Device Messages (Commands and Device Responses)
Device messages are transferred via the USB interface, the LAN interface (VXI-11 pro-
tocol) or on the data lines of the GPIB bus, the "ATN" control line not being active.
The ASCII character set is used. A distinction is made according to the direction in which
device messages are transferred:
●
Commands
Messages
