ABB COMMANDER 300 Operating Instructions Manual

Also see for COMMANDER 300: Programming guide

Contents

46 PROTOCOLThe protocol used is based on ANSI-X3.28-1976-2.5-A4 and is used for master (hostcomputer) to slave (C300 Controller)systems. This is the recommended protocolfor use with supervisory systems such as ABBKent-Taylor PC30. The Protocol is:Start transmission (STX) – Command –Identification … End transmission (ETX)– see Figs. 8.1 to 8.6 on pages 7 and 8.Transmission of commands and processingof the subsequent replies must beincorporated into the host computerprogramme.5 SETTING UPFor all aspects other than serial datatransmission the controller is set up asshown in the Operating Instructions (IM/C300). Unless otherwise requested, theinstrument is despatched with atransmission rate of 9600 baud andtransmission line termination resistorslinked-out. If the resistors are to be linked-in(see Fig. 4.2) carry out the following section.5.1 TerminationResistors – Fig. 5.1For long transmission lines, terminationresistors are required on the last C300Controller in the chain and at the hostcomputer/computer terminal – see Fig. 4.2.Under normal operating conditions theresistors are required at the receive inputsonly. The controller’s resistors are selectedusing plug-in links – see Fig. 5.1.Switch off the supply and remove thecontroller from its case (Fig. 2.1 in theOperating Instructions, IM/C300). Set thetermination resistor links as shown inFig. 5.1.Fig. 5.1 Selecting the Termination Resistors2IdentifyLinks1 84 51 84 51 84 53TerminationResistorsLinked-outInvertControllerPosition linksTerminationResistorsLinked-in1