Reference
Remote Communication
You may want to integrate your oscilloscope into a system environment and
remotely control your oscilloscope or exchange measurement or waveform
data with a computer. You can control your oscilloscope remotely via the
IEEE Std 488.2–1987 (GPIB) interface.
GPIB enables data transfers between instruments that support the GPIB
protocols. It provides:
Remote instrument control
Bidirectional data transfer
Device compatibility
Status and event reporting
Besides the base protocols, Tektronix has defined codes and formats for
messages to travel over the GPIB. Each device that follows these codes and
formats, such as the TDS 620A, TDS 640A, TDS 524A, & TDS 644A, sup-
ports standard commands. Use of instruments that support these commands
can greatly simplify development of GPIB systems.

GPIB Interface Requirements

You can connect GPIB networks in many configurations if you follow these
rules:
No more than 15 devices, including the controller, can be on a single bus.
Connect one device load every two meters (about six feet) of cable length
to maintain bus electrical characteristics. (Generally, each instrument
represents one device load on the bus.)
The total cumulative cable length must not exceed 20 meters (about
65 feet).
At least two-thirds of the device loads must be turned on when you use
your network.
There must be only one cable path from each device to each other device
on your network (see Figure 3-64), and you must not create loop configu-
rations.

GPIB Protocol