Logix5000 Controllers General Instructions - SLAC Confluence

Input/Output Instructions (MSG, GSV, SSV, IOT) 183Attribute Data Type Instruction DescriptionErrorDetection SINT GSV Specifies the error-detection scheme.Value: Meaning:0 BCC (default)1 CRCMasterMessageTransmit SINT GSV Current value of the master message transmission (master only).Value: Meaning:0 between station polls1 in poll sequence (in place of master’s stationnumber)Default is 0.NAKReceiveLimit SINT GSV The number of NAKs received in response to a message beforestopping transmission (point-to-point communication only).Valid value 0-127. Default is 3.NormalPollGroupSize INT GSV Number of stations to poll in the normal poll node array afterpolling all the stations in the priority poll node array (master only).Valid value 0-255. Default is 0.PollingMode SINT GSV Current polling mode (master only).Value: Meaning:0 message-based, but don’t allow slavesto initiate messages1 message-based, but allow slaves toinitiate messages (default)2 standard, single-message transfer per node scan3 standard, multiple-message transfer per node scanDefault setting is 1.ReplyMessageWait DINT GSV The time (acting as a master) to wait after receiving an ACKbefore polling the slave for a response (master only).Valid value 0-65,535. Delay in counts of 20 msec periods. Thedefault is 5 periods (100 msec).StationAddress INT GSV Current station address of the serial port.Valid value 0-254. Default is 0.SlavePollTimeout DINT GSV The amount of time in msecs that the slave waits for the master topoll before the slave declares that it is unable to transmit becausethe master is inactive (slave only).Valid value 0-32,767. Delay in counts of 20 msec periods. Thedefault is 3000 periods (1 minute).TransmitRetries SINT GSV Number of times to resend a message without getting anacknowledgment (master and slave only).Valid value 0-127. Default is 3.PendingACKTimeout DINT SSV Pending value for the ACKTimeout attribute.Publication 1756-RM003I-EN-P - January 2007