Communicate With I/O Modules - Parker H Series Installation & Service Instructions Manual

2-10 What is the H Series Fieldbus DeviceNet Adapter?
See the I/O Status Word Bit Defi nitions table for defi nitions of the fi rst
2 bytes of each I/O message produced by the adapter on DeviceNet.
I/O Status Word Bit Defi nitions
Byte Bit Operating Mode
0 0 0 = Run mode
1 = Idle mode
0 1 1 = Device failure
(at least one
device failed)
0 2 1 = Communication
failure
0 3 1 = Duplicate node
address failure
0 4 Reserved
0 5 Reserved
0 6 Reserved
0 7 Reserved
1 0 Reserved
1 1 Reserved
1 2 Reserved
1 3 Reserved
1 4 Reserved
1 5 Reserved
1 6 Reserved
1 7 Reserved
The fi rst 2 bytes of output data on the DeviceNet network that are
sent to the adapter are reserved as a command word. No bits have
been defi ned.
Publication PSS-UM001A-EN-P – December 2016
Operating Mode Description
Run - The adapter maps output
data to each module on PointBus.
Idle - Output data with zero length
is sent to I/O modules.
Device Failure - One or more of the
devices in the scanlist has failed to
communicate with the adapter.
Communications Failure - The
adapter has entered the BUSOFF
state on the Subnet. Another
Subnet device is confi gured with
the wrong baud rate.
Duplicate Node Address Failure -
There is another node with the
same address (0) as the scanner
on the Subnet and the adapter has
failed its Dup_MAC_ID test.

Communicate With I/O Modules

The adapter module supports multiple communication choices.
These choices all use the default I/O structure previously described.
The adapter's master (e.g., 1756-DNB) makes the actual
communication choice. The choices are:
• Polled – Adapter sends data in response to received data.
• Strobe – Adapter sends data in response to the strobe
command. The single bit allocated to the adapter in the strobe
message is not used. If the confi gured size of the input data
(sent from the adapter) is greater than 8 bytes, the strobe
connection establishment will fail. In this case, the input size
must be reconfi gured to 8 bytes or less (only 6 bytes are I/O
data because the fi rst 2 bytes are the status word).
• Change of State – Adapter sends data based on detection
of any changed value within the input data.
independently received based on change of state from the
sender. Data in both directions can be acknowledged or
unacknowledged depending on the run time confi guration of
the system.
• Cyclic – Adapter sends data cyclically based on a confi gured
time value. Data is independently received cyclically from
the sender. Data in both directions can be acknowledged or
unacknowledged depending on the run time confi guration of
the system.
The adapter uses these messages to solicit data from or deliver
data to each device. Data received from the devices (i.e., input
data) is organized by the adapter and retransmitted to the master.
Data received from the master (i.e., output data) is organized in the
adapter and sent on to the I/O modules.
Data is