Publication PSS-UM001A-EN-P – June 2005
2-2
What is the Isysnet DeviceNet Adapter?
1. Set Subnet/Backplane Baudrate
The adapter and Subnet/Backplane modules must use the same
baudrate to communicate with each other. Use one or both of the
following to set a Subnet/Backplane baudrate.
• Enable or disable the Backplane Autobaud feature for Isysnet
I/O modules. Isysnet I/O modules have Autobaud enabled
as the default - See page 2-5.
• Set the adapter baudrate for the Subnet. The default for the
PSSCDM12A and PSSCDM18PA is 1Mbaud.
You set the backplane baudrate for the PSSCDM12A and
PSSCDM18PA.
2. Set Subnet/Backplane I/O Module Addresses
Once the adapter and Isysnet I/O modules are communicating at
the same rate on the backplane, you must make sure all modules
use a valid MACID.
Set the Auto Address feature for Isysnet I/O modules - See
page 2-5.
3. Configure the Subnet I/O
In the first two steps, you set a consistent communication rate and
made sure each module uses valid addresses for communication.
Next you must configure the PointBus (e.g., set scan list).
You can configure the PointBus using one of two methods:
• Auto Start Mode (ASM) or
• Manually For more information on configuring the PointBus,
see Chapter 3 for ASM or see Chapter 4 for manual
configuration.
4. Configure the Primary DeviceNet Network
Finally, you must configure the adapter for communication with a
master (e.g., Rockwell Automation 1756-DNB).
For more information on configuring the DeviceNet network, see
Chapter 5, Add the Isysnet DeviceNet Adapter to the DeviceNet
Scanner’s Scanlist.
You must understand all of the adapter’s features to effectively use
it in your Isysnet I/O system. Keep these four steps in mind as you
read this manual:
1. Set Subnet/Backplane Baudrate
2. Set Subnet/Backplane I/O Module Addresses
3. Configure the Subnet I/O
4. Configure the Primary DeviceNet Network
Remove and Reinsert Modules on the Backplane
Removal and Insertion Under Power (RIUP) is not recommended in
a Isysnet System because of the following reasons.
• Removing a module breaks the IP67 seal.
• Removing a module breaks the backplane bus. Modules to
the right of the removed module will be ‘lost’ to the adapter.
Also, the terminating resistor will be removed, causing
system uncertainty.
• Inserting a module under power may cause the adjacent
module to reset due to the addition of a large capacitive load
on the power bus.
IMPORTANT
If the module is removed while it is under power, all the modules
to the right of the removed module will disconnect from the
PointBus and field power until the module is reinstalled.
If you must remove and reinsert modules, we recommend the following:
• Do not move I/O modules to different locations on the
mounting base after they have been installed and configured.
• If adjacent modules (i.e., 2 or more) are removed from the
backplane, replace all of them before attempting to operate
the Isysnet I/O system. Input data will hold last state until all
previously removed modules are replaced.
–
If adjacent modules are removed and all but one is
returned, the adapter cannot verify the location of the
returned modules. For example, if modules are removed
from nodes 3 and 4 and only the module from node 4 is
returned, the adapter cannot verify the location. In this
case, the adapter alerts you via a flashing red PointBus
status LED that it cannot verify the presence of modules
in the affected locations. I/O data will not be exchanged
with this node until both modules have been reinserted.
–
If modules of
different types
are removed and returned
to the wrong locations, the adapter identifies the returned
modules and alerts you (via RSNetWorx for DeviceNet)
that the error has occurred and must be corrected.
–
If modules of the
same type
are removed and returned to
the wrong locations, the adapter identifies the returned
modules, updates their MACIDs, and continues operation.
IMPORTANT
The removal and return scenario exists whether the system is
under power or not. If the system is under power, the scenario
arises immediately. If the system is not under power, the
scenario arises in the next power cycle.Also, the example
above shows removal of two adjacent modules. The scenario
described exists anytime 2 or more adjacent modules are
removed and all are not returned.
IMPORTANT
Care must be taken when replacing backplane I/O modules.
Each I/O module stores its configuration parameters in internal
non-volatile memory. You must either enable ADR for all modules
or manually configure each module in a non-manufacturing
environment when the module is being replaced or placed on
the network for the first time. Failure to do so could result in
inadvertent control attributed to different configuration settings.