National Instruments GPIB-120B Manual

Also see for GPIB-120B: User manual Installation guide

Contents

National Instruments GPIB-120B Manual Manual pdf 12 page image

Chapter 1 Introduction© National Instruments Corporation 1-3 GPIB-120B User ManualWith the GPIB-120B, it is possible to overcome the followingtwo configuration restrictions imposed by the ANSI/IEEE Standard488.1-1987:• An electrical loading limit of 15 devices per contiguous bus.• A cable length limit of 20 m total per contiguous bus or 2 m times thenumber of devices on the bus, whichever is smaller.With each GPIB-120B, you can add up to 14 additional devices to the bus.The GPIB-120B appears as a device load on each side of the expansion;therefore, one GPIB-120B increases the maximum load limit from15 devices to 28 devices. The cable length limit for the system is alsoincreased an additional 4 m to 20 m, depending on the number of deviceson that side of the expansion.All signal expansion is bidirectional, meaning that Controllers, Talkers,and Listeners can be on either side of the expander. The GPIB-120Blight-emitting diodes (LEDs) indicate the location of the SystemController, Active Controller, and Source Handshaker, with respect tothe two sides of the expansion.Because the GPIB-120B is a functionally transparent expander, the sameGPIB communications and control programs that work with an unexpandedsystem can work unmodified with an expanded system.What You Need to Get Started❑ GPIB-120B❑ 10–18 VDC 9 W power supply❑ Standard GPIB cables to connect both sides of the GPIB-120B to buseson either side