Remote Control Interfaces and Protocols
R&S
®
NRP Series
45
Getting Started 1419.0170.02 ─ 10
Socket communication requires the specification of the port (commonly referred to as
port number) and of "SOCKET" to complete the VISA resource string with the associ-
ated protocol used.
The default port for socket communication is port 5025.
For details of the socket communication, refer to
Chapter 7.2.4, "Socket Communica-
Example:
A power sensor has the IP address
10.111.11.20
; the valid resource string using
VXI-11 protocol is:
TCPIP::10.111.11.20::INSTR
The DNS host name is
nrp18sn-100001
; the valid resource string is:
TCPIP::nrp18sn-100001::hislip0 (HiSLIP)
TCPIP::nrp18sn-100001::inst0 (VXI-11)
A raw socket connection can be established using:
TCPIP::10.111.11.20::5025::SOCKET
TCPIP::nrp18sn-100001::5025::SOCKET
7.2.2
VXI-11 Protocol
The VXI-11 standard is based on the ONC RPC (Open Network Computing Remote
Procedure Call) protocol which in turn relies on TCP/IP as the network/transport layer.
The TCP/IP network protocol and the associated network services are preconfigured.
TCP/IP ensures connection-oriented communication, where the order of the
exchanged messages is adhered to and interrupted links are identified. With this proto-
col, messages cannot be lost.
7.2.3
HiSLIP Protocol
The HiSLIP (high-speed LAN instrument protocol) is the successor protocol for VXI-11
for TCP-based instruments specified by the IVI foundation. The protocol uses two TCP
sockets for a single connection - the first for fast data transfer, the second one for non-
sequential control commands (e.g.
Device Clear
or
SRQ
).
HiSLIP has the following characteristics:
●
High performance as with raw socket network connections
●
Compatible IEEE 488.2 support for Message Exchange Protocol, Device Clear,
Serial Poll, Remote/Local, Trigger, and Service Request
●
Uses a single IANA registered port (4880), which simplifies the configuration of fire-
walls
●
Supports simultaneous access of multiple users by providing versatile locking
mechanisms
●
Usable for IPv6 or IPv4 networks
Ethernet Interface
