Lakeshore 620 User Manual
                                                                                          | |
Contents
| 
Lake Shore Model 620/622/623/647 Magnet Power Supply User’s ManualMainframe Control Bus OperationB-2B4.0 CONTROL BUS SERIAL INTERFACE CONFIGURATIONConfigure the control bus serial interface for either RS-232C or RS-485 communications with DIP switches onthe Communications Processor Board (CMP). The CMP plugs into the Mainframe rear panel. The standardcontrol bus serial interface configuration is RS-485. Use the procedure below to change or verify the serialinterface configuration.1. Turn off Mainframe and unplug the power cord.2. Loosen the two screws that secure the CMP tothe rear panel and slide the CMP out.3. Locate and configure the control bus serialinterface DIP switches as defined in the table tothe right. The DIP switches are just inside theCMP front panel. Switches 1-4 define theinterface as RS-232C. Switches 5-8 define theinterface as RS-485 multidrop. Switch 8activates 100Ω bus termination for long serialinterface runs. For RS-485, terminate extremelylong main lines at the furthest point from thehost. Limit main line length to under 4000 feetand multiple short stub lines from the main line(Mainframe to Mainframe) to under 50 feet. A typical RS-485 configuration runs the main line from thehost to one of the first Mainframe serial interface jacks; a Model 2001 cable plugs into the other firstMainframe serial interface jack to connect to the second Mainframe, and so on. Connect up to 32Mainframes in this way. Terminate the last Mainframe only if it is a significant distance from the host.Assign unique addresses to multiple Mainframes on a RS-485 interface.4. Replace the CMP.B5.0 SELECTING THE CONTROL BUS SERIAL INTERFACE ADDRESSMultiple Mainframes on the RS-485 interface each have a unique address and operate in a polled mode. Setthe MPS Mainframe to respond to one of 32 addresses. Prefix all commands sent to a Mainframe with theMainframe address. A Mainframe query response includes the address prefix if the address is not 0. Thereceipt of the LF (0AH) terminator resynchronizes communications and alerts all Mainframes that the nextcharacter is an address. A Mainframe with address 0 responds to all commands on the interface. A Mainframeusing RS-232C can be given a unique address as well, but RS-232C is not suited for multi-drop operation.Access the Control Bus serial interface address from the Interface Setup screen. Press the Function Menukey to display Function Menu 1. Press the key corresponding to INTERFACE SETUP to display the InterfaceSetup screen.Use the cursor key to move to the line indicating CB DEF and CB ADD; defined as follows.CB DEF: 9600 Baud, No Parity, 8 Data Bits, and 1Stop BitControl Bus Definition. The control bus should bedefined as above.CB ADD: 0 to 32Control Bus Address. Use the Data Entry up ordown arrows to increment or decrement the Control Bus Address. The initial condition is 0.CMPConfigurationDIP SwitchRS-232C TerminatedRS-485UnterminatedRS-4851 Closed Open Open2 Closed Open Open3 Closed Open Open4 Closed Open Open5 Open Closed Closed6 Open Closed Closed7 Open Closed Closed8 Open Closed Open # ! # $ # % & ' ( ) ) * ) ' ( ) ) + ) ' ( # # % & |
Related manuals for Lakeshore 620
manualsdatabase
Your AI-powered manual search engine