1. European Organization for Nuclear Research Geneva - Switzerland Ing. Robert van der Vlugt CERN/PH Alice Detector Control System PVSS2 General Purpose Interface for serial devices Date: 17.06.2004 Serial device: a device which communicates with the outside world through an interface where the data are shifted in and out in a serial way (one after the other) Most successful serial data standard for PC and telecom applications is RS-232. Similarly, RS-485 and RS-422 are among the successful standards for industrial applications. The standards are not directly compatible. Examples of serial devices: The PC mouse, modems, numerous measurement equipment, (volt/ampere meters, multimeters) PC controlled industrial equipment, etc. RS-232: single-ended signals standard for serial communication with Baud rates of 2400 to 19200 over distances from 900 to 15 meters. Data-rate capability of about 1Mbps. RS-422: differential signals standard for transmission over much greater distances. RS-485: improved version of the RS-422 standard for longer line lengths and more nodes on a bus system. For more info: type: “how to”, RS-232, RS-422, RS-485 in Goooooogle Serial Devices 1

2. European Organization for Nuclear Research Geneva - Switzerland Ing. Robert van der Vlugt CERN/PH Alice Detector Control System PVSS2 General Purpose Interface for serial devices Date: 17.06.2004 PVSS2 and serial devices Serial devices may be connected to the PVSS2 SCADA system in several ways: 1.Use the COM port of the PVSS2 controller and access the device with the IEC driver. IEC stands for International Electrotechnical Commission, which has given its name to the protocol IEC 60870-5-101for serial connections. See under PVSS2 management and drivers. 2.Use the PVSS2 Applicom driver and an Applicom PCI-1000 card. See under PVSS2 management / Drivers and the Applicom website. 3.Use the PVSS2 OPC client connected to a Matrikon OPC server talking a RS-232 protocol to a COM port. See under PVSS2 management / OPC and the Matrikon website. 4.Use a virtual COM port in the PVSS2 controller. The serial port of the device connects to a special card, which communicates via TCP-IP (LAN) with the virtual COM port in the controller. This could be seen as a remote extension of a COM port. See under www.digi.com/productswww.digi.com/products and then Terminal Servers/Portserver TS2/4. There are more solutions, however the above mentioned use the software resources, which come with PVSS2. 2

3. European Organization for Nuclear Research Geneva - Switzerland Ing. Robert van der Vlugt CERN/PH Alice Detector Control System PVSS2 General Purpose Interface for serial devices Date: 17.06.2004 The Heinzinger PNC 150000KV Very High Voltage supply This power supply will provide a 100KV DC voltage to the central electrode of the Alice TPC Field Cage. It will be accessed by the DCS via an RS-232 interface and controlled by an SCPI commands set. SCPI stands for Standard Commands for Programmable Instruments, which is a sort of IEEE 488.2 (GPIB) like commands set. SCPI commands: These are alpha-numerical strings as: VOLT_10000 or MEAS:CURR?, which means set 10KV at output and measure actual output current. Selected Interface Option: IEC driver in PVSS2 with a redundant controller PC. Present Status: Controller PC loaded with PVSS2 version 3.0 and starting to setup test project using the IEC driver. Future Activities: Implement the full control of this device with the IEC driver in PVSS2. Propose a common solution for serial devices, which can be included in the IT-CO Framework for PVSS2. 3

4. European Organization for Nuclear Research Geneva - Switzerland Ing. Robert van der Vlugt CERN/PH Alice Detector Control System PVSS2 General Purpose Interface for serial devices Date: 17.06.2004