European Organization for Nuclear Research Geneva - Switzerland Ing. Robert van der Vlugt CERN/PH Alice Detector Control System Serial Communication, simple, reliable and over long distances. Date: 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 100 to Baud over distances from 900 to 15 meters. Data-rate capability of about 1Mbps. RS-422: differential signals standard for transmission over greater distances. RS-485: improved version of the RS-422 standard for even 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 Communication, RS-232…..and more 1

European Organization for Nuclear Research Geneva - Switzerland Ing. Robert van der Vlugt CERN/PH Alice Detector Control System PVSS2 and Serial Devices Date: Connection of Serial Devices Serial devices may be connected to the PVSS2, SCADA system in several ways: 1.Use the RS-232 (COM) port of the PC controller and access the device with a Control Script under PVSS2 (Max. cable length between PC and device about 15 m) 3.There are several drivers available under PVSS2, such as the Applicom, ModBus or ProfiBus driver, which all require an interface card for the connection of a serial device to the PC controller. 2. Talk to the serial device as under point 1 and re-direct the communication to a device on the Ethernet, which converts the protocol from Ethernet to Serial for the connected device. This can be seen as a remote COM port for the PC controller. See under ww…digi.com/products and then Terminal Servers/Portserver TS2/4. 2 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) Communication with Serial Devices PVSS2 accesses the serial devices with the V24 control functions for open(), close(), read(), and write(), which are available in the Control Language.

European Organization for Nuclear Research Geneva - Switzerland Ing. Robert van der Vlugt CERN/PH Alice Detector Control System Controller PC or Workstation WinXP PVSS2 EtherNet Ethernet/Serial Converters (Digi-One SP with Firmware) Serial Device (Heinzinger VHV) VHV application “talks” to PC’s local COMport and data is re-directed via ethernet and a converter to the serial device. Digi-One software for serial re-direction (See Re-direction of Serial Communication Date: A

European Organization for Nuclear Research Geneva - Switzerland Ing. Robert van der Vlugt CERN/PH Alice Detector Control System PVSS2 and the Heinzinger PNC 150 KV Supply Date: The Heinzinger PNC, 150 KV 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 (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: re-direction to remote COM port via Ethernet Present Status: Controller PC loaded with PVSS2 version 3.0 and a remote COM port (DIGI-One SP) is installed and configured. Future Activities: Develop software (Control Scripts and/or C++) for the control and utilization of the 150 KV, HV Supply. 3

European Organization for Nuclear Research Geneva - Switzerland Ing. Robert van der Vlugt CERN/PH Alice Detector Control System More Serial Communication? Why not…….. Date: The RS-232 Serial Communication Protocol is widely used for the control and data-acquisition of industrial processes, if sampling rates for parameters are less than once per second. It is not only applied in industry, but also in cars, houses, schools, security, water treatment, traffic control, medical equipment and many more domains…. The communication is simple, reliable and can bridge hundreds of kilometers via Ethernet, radio transmission and VHF line-of-sight links. A good example is the FieldPoint system from National Instruments (NI), which connects just one COM port to a total of 225 modules (max.16 chan’s/mod), which accept all types of signals. The most recent versions of FieldPoint do not only collect data, but dispose also of local control resources (PLC or computer-like device) It comes with reliable software for installation, configuration, utilization and NI provides an OPC server, which can be directly connected to PVSS2. The system is not radiation hard, as it is meant for industry. However, the potential market for serial devices at CERN (four huge detectors and the LHC machine) is big enough for negotiating a rad hard version for a slightly higher price.

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: End of Presentation……..