Basic Instrument Functions
R&S
®
CMW500
108
User Manual 1173.9463.02 ─ 02
External Ref. Frequency
Value of the external reference frequency. If "Frequency Source: External" is used this
value must be equal to the frequency of the signal fed in at the rear panel connector REF
IN. Besides the external reference signal must meet the specifications of the data sheet.
Note:
If synchronization fails, or if no external signal with the correct frequency is avail-
able, the red "ERROR" LED at the front panels lights; see
. The "frequency locked" state can also be checked via command, see below.
SCPI command:
SYS SYNC
This setting is only present if the R&S CMW500 is equipped with a "Multibox Flexible Link
Sample Bus Board with external SysSync Support" (option R&S CMW-S550M).
The parameter specifies the mode of system time synchronization. It is essential when
switching between single-CMW and multi-CMW setups. A multi-CMW setup will use two
or more interconnected R&S CMW instruments. Several instruments communicate with
each other using a LAN connection between the rear panel LAN SWITCH connectors.
All connected instruments have to share the reference frequency and the system syn-
chronization signal. If the time information is not synchronized between instruments, test
runs may fail or logging information cannot be evaluated, for example.
Note:
Only use the cables labled SYS SYNC which are included in the delivery.
If synchronization fails or if no synchronization signal is available, the red "ERROR" LED
at the front panels blinks. See the error message in the "CMW" application for error
details.
For example multi-CMW test setups, refer to the "Protocol Testing - Test Setups and Use
Cases" manual.
"Standalone"
The instrument will use its internal synchronization signal.
"Generator"
The instrument provides a system synchronization signal at the three
rear panel connecters SYS SYNC OUT 1 to SYS SYNC OUT 3. It then
provides identical time information to all connected R&S CMW instru-
ments, including itself, using the rear panel connector SYS SYNC IN.
"Listener"
The instrument receives a time synchronization signal at SYS SYNC IN
from another R&S CMW that is configured as "Generator".
SCPI command:
5.3.7 External Trigger
The R&S CMW500 supports input and output trigger signals:
1. An input trigger signal is used to synchronize an R&S CMW500 measurement to an
external event. E.g. a DUT providing a frame-periodic RF signal may generate an
additional trigger signal to indicate its frame timing.
Setup Dialog
