Annexes
R&S
®
ZNA
1646
User Manual 1178.6462.02 ─ 20
EMI Suppression
Use only double shielded cables or disconnect the input pins of the User Port connec-
tor to avoid spurious input signals which may cause undesirable events.
This is of particular importance for the external trigger input (pin no. 2) if the Trigger In
input is used.
12.3.1.2
Trigger In
BNC female connector for external trigger input; see
"FreeRun / External / Manual /
on page 506. The external trigger input signal must be a 3.3 V or 5 V
TTL signal with a minimum pulse width of 1
µ
s. The trigger input has a high input impe-
dance (> 10 k
Ω
).
12.3.1.3
Trigger Out
BNC female connectors for external trigger output; see
The R&S
ZNA trigger output provides a configurable 5 V TTL trigger signal. The output
impedance is approximately 50 Ohm.
12.3.2
LAN interface
To be integrated in a LAN, the instrument is equipped with a LAN interface, consisting
of an RJ-45 connector, a network interface card and protocols. The network interface
card supports IEEE 802.3 for a 10 Mbps Ethernet and IEEE 802.3u for a 100 Mbps
Ethernet.
Instrument access is possible via the VXI-11 protocol. It is usually achieved from high
level programming platforms by using the Virtual Instrument Software Architecture
(VISA) library as an intermediate abstraction layer. VISA encapsulates the low-level
function calls and thus makes the transport interface transparent for the user. See also
Chapter 6.1, "Introduction to remote control"
12.3.2.1
VXI-11 interface messages
The following VXI-11 interface messages (also termed low-level control messages) are
also supported by the GPIB Explorer.
Command
Meaning
Effect on the instrument
@DCL
Device Clear
Aborts the processing of the commands just received and sets
the command processing software to a defined initial state.
Does not change the instrument settings.
@GET
Group Execute
Trigger
Triggers the active measurement sequence (e.g. a sweep).
The effect of the command is the same as with that of a pulse
at the external trigger signal input.
Interfaces and connectors