raw socket Instruments
For instruments that use raw socket protocol, the
4865B transparently transmits GPIB device messages
to the instrument. Instrument responses are received
from the instrument and outputted to the GPIB Control-
ler when the 4865B is addressed to talk. The 4865B
can be set to use a specific raw socket port number, to
recognize an EOS character to terminate the instrument
responses and to test the instrument's IDN response. If
the instrument supports the VXI-11 Discovery method,
the 4865B can AutoFind it. The 4865B can also convert
IEEE-488.1 GPIB Commands such as GET, SDC, etc.
and GPIB events such as IFC or local/remote changes
into a user specified command strings if the instrument
has similar capabilities. If SRQs and Serial Polls are
enabled, the 4865B performs a background check of the
instrument's Status Register with the *STB? query to
create a virtual Status Byte Register and asserts an SRQ
on the GPIB bus when a Service Request is detected.
Minimal Programming changes
In most cases, existing programs that run the new
Ethernet version or the older GPIB version of the instru-
ment can be used with the 4865B and the new instrument.
The only requirement is that the new instrument must
understand the existing commands. The 4865B works with
any IEEE-488.2 compatible GPIB controller and can be used
with LabVIEW, VEE, Visual Basic and C language programs.
The 4865B and VXI-11.3 instrument combination supports
most 488.1 GPIB commands except for Remote with Lockout
and Local with Lockout.
When used with a raw socket instrument, the combination
will have reduced GPIB capability that can be augmented
when configuring the 4865B. Depending upon the instrument's
capability, the user can enable AutoFind, IDN queries, IDN
confirmation, SRQ generation and Serial Polling. The 4865B
can also be set to send the instrument substitute command
strings for Device Trigger, Device Clear, GTL, Local/Remote
changes, IFC received and power turn-on or reset.
connections
While the 4865B is normally used in a back-to-back con-
nection with its companion instrument as shown in Figure 1,
it can be connected to the instrument in other ways. Figure
2 shows the 4865B connected to the instrument through an
Ethernet hub or switch. This is a typical lab bench connec-
tion. It lets a user configure the 4865B through the hub while
developing the GPIB program.
The 4865B instrument connection can be expanded across
the company network as shown in Figure 3 or further if the
instrument is VXI-11 compatible. The 4865B provides standard
GPIB control over the instrument no matter where it is located.
Figure 2 4865B Instrument Hub Connection
Figure 3 4865B Instrument Network Connection
4865B APPLICATIONS
setup & Installation
The 4865B is very easy to install. Plug the 4865B into a
network access point adjacent to your computer as shown in
Figure 2 or use an Ethernet cable to connect the 4865B directly
to a PC's network port. Launch a web browser and point it
to the 4865B's default AutoIP address of 169.254.48.65. The
4865B's Welcome page provides all of the information about
the 4865B's current settings. If the 4865B is being used with
a VXI-11 compatible instrument that has an AutoIP address,
no configuration is required.
Else, select the Configuration Page where you can select
and set a static IP address or DHCP with AutoIP, change the
4865B's GPIB address, enable AutoFind or set a fixed IP ad-
dress for the companion instrument, and select the instrument
protocol (VXI-11 or raw socket). For raw socket instruments,
you can enter strings that the instrument can respond to. The
4865B will send the strings to the instrument in place of
GPIB Commands or events. For instance, the IEEE-488.2
*RST Common Command might be replaced with 'Reset'.
Set the remaining parameters, save the settings, reboot and
the 4865B is ready to be connected to the instrument and to
the GPIB bus.
A rear panel LAN Reset button is provided to reset the
4865B's network settings to the factory default settings in
case the 4865B's configuration needs to be reset.
4865B LAN <=>GPIB Interface
GPIB
LAN Instrument
Line to Company Network
8065 Ethe
rnet to GPIB
Ethernet Cables
4865B LAN <=>GPIB Interface
GPIB
LAN Instrument
8065 Ethernet
to GPIB
Company Network
