Specifications

Connection Example
142
890USE17700 September 2003
The I/O modules in the sample assembly have the following island bus addresses:
The PDM and the termination plate are not addressable (See Addressable Modules,
p. 46).
Modbus over
TCP/IP View of
the Sample
Island
Configuration
The order in which the Advantys STB I/O modules in the sample island (See
Example, p. 141) are physically assembled determines the order in which data will
appear in the input and output data image areas (See The Island’s Process Image
Blocks, p. 169) of the process image.
input data includes all of the I/O modules on an Advantys STB island bus that
contain status, data, and/or echo output data
output data contains only data
No bit-packing is used.
Standard Modbus 4x and 3x message formats are the addressing mechanism.
Input Process
Image
The I/O modules in the sample island (See Example, p. 141) require 18 Modbus
registers in the input data image area (See The Input Data and I/O Status Process
Image, p. 120). The following table shows how these registers are organized:
I/O Model Module Type Module’s Island
Bus Address
Module’s Island
Bus Address
STB DDI 3230 two-channel digital input 1 N1
STB DDO 3200 two-channel digital output 2 N2
STB DDI 3420 four-channel digital input 3 N3
STB DDO 3410 four-channel digital output 4 N4
STB DDI 3610 six-channel digital input 5 N5
STB DDO 3600 six-channel digital output 6 N6
STB AVI 1270 two-channel analog input 7 N7
STB AVO 1250 two-channel analog output 8 N8
Modbus
Register
151413121110987654321 0
45392 empty–set to 0 N1 data
STB DDI 3230 data
45393 empty–set to 0 N1 status
STB DDI 3230 status
45394 empty–set to 0 N2 echo
STB DD0 3200 feedback
45395 empty–set to 0 N2 status
STB DD0 3200 status