GPIB TO SERIAL CONVERTER

In recent years, many PCs and devices with serial communicationinterface have been adopted in the lower layer of Accelerator control systems. By the reason of the simplicity, reliability, and the low cost, the device with serial communicationinterface will be utilized more and more in accelerator control systems and physics experimental facilities. As a solution of the method for connecting a large number of devices with one PC, a GPIB to serialconverter has been developed. The converter is equipped with RS-485transceiver. The transmitter and receiver are automatically being switched according to the GPIB commands (talker, listener, EOI). With this converter, 32 RS485 devices can be controlled through one GPIB node on a multi-drop serialline with maximum length of 1200m. The communication with serialdevise is similarly carried out of the device message of GPIB communication. As one GPIB controller can be connected directly with 15 GPIB to serialconverters, so the number of connected serialdevices becomes 480. For even higher demand to connect devices to one controller, combinations of the GPIB address converter (presented ICALEPCS2001) and GPIB bus-extender can be used. With this, the maximum number of devices connectable to one controller extends to about 28 thousand. The GPIB to serialconverter and GPIB address converter will be used for surveillance of the utility and cross-checking of magnet power supplies in the J-PARCexperimental facilities.