Watlow Electric Gateway & DeviceNet - Manual (Page 12)

RUI/Gateway & DeviceNet TM
Configuration & Ladder Logic Example
Using an Allen-Bradley CompactLogix PLC
Watlow
1241 Bundy Blvd
Winona, MN 55987
Telephone: 507-494-5656
© 2007 Watlow Electric Mfg Co 12
4/08
22. Notice too, the slot number, in this case “1”. This is the physical slot in which the scanner
resides. After the scanner is configured two tags will be automatically generated reflecting the
existence of the scanner in slot 1 of the I/O structure. These tags will be used to move the
implicit input and output assemblies (more on this to follow) to and from the RUI/Gateway and
then ultimately to the destination EZ-ZONE
® PM controls that exist on Standard Bus.
23. Before we get started with the programming examples it is important to note that the EZ-
ZONE
®
family of controls has an on-board EEPROM to back up user settings in the event of
a power loss. By default, the non-volatile save parameter is enabled, therefore changes made
over the network as well as any changes made from the RUI are saved to the EEPROM. If
the implicit output (PLC to EZ-ZONE
®
Control) assembly is in use, where information is
exchanged implicitly (continuously after the connection is established) the rate at which writes
to EEPROM occur could be very fast. With this being said, it should be considered carefully
as to whether or not this parameter should remain enabled. To avoid premature EEPROM
failure (~1,000,000 writes) it is recommended that the user disable the non-volatile write
parameter in the destination nodes residing on the Standard Bus side of the RUI/Gateway. An
example will follow showing how to read and write to this parameter.
EZ-ZONE
®
EEPROM