Model 671 User’s Manual REMOTE COMMUNICATIONS
Bristol Instruments, Inc. 31
Direct Communication
The 671 system can transfer measurement data to a PC or be sent commands and
queries by a PC using the USB or Ethernet interfaces. Connections for the USB and
Ethernet interfaces are located on the back panel of the instrument. The Standard
Commands for Programmable Instruments (SCPI) communications scheme is used to
communicate with the 671 system.
USB Interface
The USB connection to the PC uses an RNDIS driver for virtual Ethernet connection. The
RNDIS driver is included with every Windows PC, but it may not be activated. If you
encounter errors with connecting the PC to the instrument, this may be a result of an
inactive RNDIS driver. Please see Appendix C for information describing how to activate
the RNDIS driver.
Ethernet Interface
The 671 Laser Wavelength Meter is a Telnet server, using the default Telnet port 23.
• Cabling – The Ethernet port of the model 671 can be connected to the network hub
or switch using a straight-through CAT-5 Ethernet cable since regular ports (non-
uplink) on all hubs and switches are already crossed-over by default. A crossover
cable is required if, and only if, Auto-MDIX is not supported.
• IP Address Set-Up – The IP address for the 671 system is assigned manually or
automatically using the Dynamic Host Configuration Protocol (DHCP) from the
Instrument menu in the NuView software.
When DHCP is enabled, the 671 system sends a broadcast query over the network
requesting necessary information from a DHCP server. Upon receipt of a valid
request, the server will assign to the 671 system an IP address, a lease (length of
time for which the allocation is valid), and other IP configuration parameters, such as
the subnet mask. The query is initiated immediately after booting, and must be
completed before the 671 system can be accessed via IP-based communication with
other hosts.
If a DHCP server is not present on the network, or if a fixed IP address is preferred,
then DHCP can be turned off by unchecking its box, and the IP address can be
assigned manually through the NuView software. It is important to assign an IP
address that is not already in use.
The Subnet Mask is also entered from the Connection Settings screen. The Subnet
Mask should match that being used by the PC, and the IP Address should fall in the
same subnet. Contact the network administrator to determine the correct setting.