National Instruments GPIB-140A/2 GPIB Extender

The NI GPIB-140A/2 (Part Numbers: 777998-01, 777998-02, 777998-03, 777998-04, 777998-05, and 777998-06) is a member of the National Instruments GPIB-140A Series. This model utilizes a fiber-optic cable and offers up to 2 km extension in terms of cable length. Without using an extender, GPIB systems cannot be deployed beyond 20 m- a limitation imposed in the IEEE 488 standard. With this GPIB Extender, two separate and remotely located GPIB systems can be joined to operate as one GPIB system.

The NI GPIB-140A/2 sends and receives data across the fiber-optic cable by using a different communication protocol. With this extension arrangement, the user can operate two devices on the same bus. This system can help users go beyond the IEEE 488 restriction of 15 devices per a contiguous bus as well. Instead, users can utilize as many as 28 devices on the same system without sacrificing performance or speed. For longer distances, users can connect multiple extenders in series. For additional loading, users can connect the devices in star patterns as well.

This device offers data transmission in two modes: buffered and unbuffered mode. In buffered mode, FIFO buffers are utilized to increase the rate for the transfer of data. In unbuffered mode, every bit of data is held by the cable until both devices (receiver and sender) verify that the message is transmitted correctly. By default, the NI GPIB-140A/2 is configured to operate in unbuffered mode. However, the can reconfigure the device with the help of the included DIP switches on the GPIB-140A/2.