Explicitly Writing To The Gateway; E X P L I C I T L Y W R I T I N G T O T H E G A T E W A Y - Conair W Series User Manual

C o n f i g u r i n g t h e D e v i c e N e t S o f t w a r e
A d d i n g t h e G a t e w a y t o t h e S c a n L i s t
( c o n t i n u e d )
6
Select the "OK" button once you have modified your input field size to
match the number of bytes shown in Parameter 7. Since the actual data size
being used differs from the maximum possible data size, you will get an error
message noting this. Click the "OK" button to keep the data size you have
entered.
7
Once the I/O parameters have been modified, the gateway may be mapped
to your desired I/O area using the Input tab. Depending on whether your
controller is 16 bit (Allen Bradley Micrologix) or 32 bit (Allen Bradley
Controllogix) the data may transfer either as individual words (16 bit) or two
parameter words may be combined into a DINT (32 bit). All parameters should
now be accessible from the programmable logic controller. (PLC)
C o n f i g u r i n g t h e D e v i c e N e t S o f t w a r e

E x p l i c i t l y W r i t i n g t o t h e G a t e w a y

As discussed above, the information from the Common Controls Systems can be
set up to be read directly as inputs in a PLC system. In order to write data to the
gateway it must be written in a DeviceNet Explicit message. The method was cho-
sen to ensure that data is written once, only when the PLC decides it should be
written. This reduces bandwidth on the network and ensures that the data is sent
only when it is required. Note that parameters 530 to 539 are set up as the registers
to write to the common controls devices. Please see your DeviceNet system
provider's information on using explicit messaging for more details.
D e v i c e N e t C o m m u n i c a t i o n s l C - 1 1