Rockwell Automation 1769-ADN Compact I/O 1769-ADN DeviceNet Adapter - Manual (Page 28)

Publication 1769-UM001B-EN-P - October 2002
2-4 How Communication Takes Place and I/O Image Table Mapping
Communication Choices The Compact I/O DeviceNet adapter module supports multiple
communication choices. These choices all use the DeviceNet adapter
input image and output image structure previously described. The
DeviceNet master makes the actual communication choice. The
choices are:
Polled 1 - data is sent by the adapter in response to received data
Strobe - data is sent by the adapter in response to the strobe
command. The single bit allocated to the adapter in the strobe
message is not used. If the configured size of the input image (sent
from the adapter) is greater than 8 bytes, only the first 8 bytes of the
input image are returned (of which, the first 4 bytes, or 2 words, are
the adapter status words).
Change of State - data is sent by the adapter based on detection of
any changed value within the input data. Data is independently
received based on change of state from the sender. Data in both
directions can be acknowledged or unacknowledged depending on
the run time configuration of the system.
Cyclic - data is sent cyclically by the adapter based on a configured
time value. Data is independently received cyclically from the sender.
Data in both directions can be acknowledged or unacknowledged
depending on the run time configuration of the system.
1 Refer to Appendix C for some important system characteristics when using the polled mode (minimum
inter-scan delay I.D. for polled connections).
Mapping I/O Data into the
Image Table All Compact I/O modules are supported by the Series B DeviceNet
adapter. At present, these consist of:
Module Description For I/O data
definition, see:
1769-IA8I Individually Isolated 120V AC Input Module (8 Point) 2-5
1769-IA16 120V ac Input Module (16 Point) (16 Point) 2-5
1769-IF4 (Series A and B) Analog Current/Voltage Input Module (4 Channel) 2-6
1769-IM12 240V AC Input Module (12 Point) 2-6
1769-IQ16 24V DC Sink/Source Input Module (16 Point) 2-6
1769-OA8 100 to 240V AC Solid State Output Module (8 Point) 2-7
1769-OA16 100 to 240V AC Solid State Output Module (16 Point) 2-8
1769-OB16 Solid State 24V DC Source Output Module (16 Point) 2-9
1769-OB16P Electronically Protected Solid-State 24V DC Output Module 2-10
1769-OF2 (Series A and B) Analog Current/Voltage Output Module (2 Channel) 2-11
1769-OV16 Solid State 24V DC Sink Output Module (16 Point) 2-12