Uniform Remote Control of Front End Processors in PAN-DA

Abstract The PAN-DA data acquisition software system encompasses support for a variety of front end processors including the Struck General Purpose Master (GPM), the Fermilab Smart Crate Controller (FSCC), and the Motorola MVME133-A VME single board computer. PAN- DA provides support for the remote control of these processors through its Remote Procedure execution (RPX) software. This software runs over serial lines, and in some PAN-DA environments, over the Ethernet and TCP/lP as well. Experiments E791 and E771 have successfully used RPX software in both FSCC software development and data collection during the 1990-1991 fixed target run at Fermilab. RPX software has facilitated development and testing of the Fermilab Silicon Strip Detector readout system, for which the FSCC is an integral component, RPX based control and monitoring of the GPM and the MVME133-A are essential parts of the PANDA data acquisition system used by E687 and E773 during the 1990.1991 run. I. INTRODUCTION Although a greater amount of intelligence is finding its way into front end processors, because of their dedicated task and real time requirements, they will always lack the full functionality of general purpose computers. Because of this, central control is usually provided by more appropriate general purpose computers. This paper discusses the software provided for controlling PAN-DA Il.21 front end processors from remote hosts. This software provides a uniform high level interface through remote procedure calls for a variety of front end processors, and a variety of other levels of communications mechanisms depending on the spccilic front end processor. Two specilic applications of the control software are presented: The PAN- DA data acquisition control and remote control of FSCCs. 1 Sponsored by DOE contracl No. DE-AC02-76CH03000 II. SYSTEM LEVEL SOFTWARE The communications software uses Software Components Group’s operating system, pSOS, and was developed with their pROBE board level debugger. The software and device drivers are developed on VAXes “sing cross tools from Microtec3, Inc., including C and Pascal compilers, assembler, librarian, and linker. Source code and product management ate also handled on the VAX. The Microtcc Run Time Library, which supports both C and Pascal, has been slightly modified to provide the process teennancy necessary for multitasking. Our embedded systems environment is supported on 68000 based processors, and has bee” ported to all PAN-DA front end processors discussed here. It integrates the operating system, the board hardware, the Run Time Library and other high level language support, utility libraries, a serial port driver, and drivers for other processor peripherals. The serial ports are accessible by standard language l/O consnwts. System PROMS provided with the FSCC [3,4] include a” Ethernet downloader called DETH [41. DETH comes up automatically when the board is reset, and listens for download requests from VAX hosts. Applications can be started automatically when downloaded by DETH, or at a later time. The MVME133-A can be downloaded over the in-house vertical bus (Branch Bus) or RS-232. The GPM can be downloaded only over RS-232. The embedded environment also provides the capability to boot applications from ROM, or other non volatile memories, by copying into RAM, or running directly out of ROM. III. COMMUNICATIONS SOFIWARE Supported front end processors are able to communicate with the outside world over RS-232, Ethernet, or both. The software we have layered on top of these two media is depicted in Figure 1. 2pSOS and pROBE are trademarks of Software Components Group, Inc. 3Microtec is a registered trademark of Microtec Research,