1771-6.5.132, PLC-5 DeviceNet Scanner User Manual

Data Map Example D-9The following is an output data mapping scheme example for ascanner in 1/2-slot addressing mode.Note: 1 word = 2 bytes1 byte = 8 bitsOutput Image Table16N1bit numbernode numberN1 = node #1Bit numbering in the data table isright to left, beginning with zero.15 0Module Statusword 023 22 21 20 19 18 17 16N15540N25word 139 38 37 36 35 34 33 32N2331 30 29 28 27 26 25 24word 2(for discrete output data bits)In 1/2-slot addressing mode, 24 bits of theoutput data table are used for the outputimage table. The image table is fordiscrete output bits. In the default mode,the processor writes the output bits of thefirst 24 nodes to the output image table viaDIO. The output bits from the remainingnodes are written to the output data table.Note that the output image table beginswith bit #16, where the output bit for node#1 (MAC ID 1) is written. The output datatable now begins with bit #40, where theoutput bit for node #25 (MAC ID 25) iswritten.Channel AChannel B95125N451437980N1word 3word 4word 5word 6word 7word 8The scanner takes the output bits from itsoutput data table and organizes them intoa strobe message. The strobe messagecontains one bit for each node address,0-63. In default mode, the scanner is node0; therefore, this bit is empty. The scannersends a separate strobe message to eachnetwork, via channel A and channel B.Output Data Strobe Message channel AEach node’s output bit is mapped to a bit number in thestrobe message that directly corresponds to thatparticular node’s MAC ID. For example, the output bitfor node #23 is mapped to strobe bit #23.Bit numbering in the data table isright to left, beginning with zero.63 - - - - - - - - - - - - - - - - - - - - - - - - - 23 - - - - - - - - - - - - - - - 1 0N23N1Output Data Strobe Message channel B63 - - - - - - - - - - - 45 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 0N45N1Publication 1771-6.5.132 - June 2000