Installing The Modbus Communication Hardware; Using The Modbus Parameter List - Conair 150 User Manual

D e s c r i p t i o n o f M o d b u s
C o m m u n i c a t i o n s
The common controls series of products from Conair use standard Modbus com-
munications protocol to allow the user to access the control boards for supervisory
type functions. For example, you may want to display the drying temperature for
all hoppers in a facility in one central location. By connecting all the dryers to a
central computer, the temperatures and setpoints can be displayed in one location
using a standard SCADA software program such as Wonderware or RSView.
Depending on the particular common controls board, the Modbus serial communi-
cation interface maybe be either RS-232 (DC-2 control board) or RS-485 (DC con-
trol board). Converters may be ordered with the product to convert from one to the
other. The RS-485 standard allows multiple controllers to be daisy-chained togeth-
er over longer distances while the RS-232 allows direct connection to most person-
al computers without an interface adapter.
I n s t a l l i n g t h e M o d b u s
C o m m u n i c a t i o n H a r d w a r e
The hardware required for Modbus communications is included with the product
when it is shipped. Connectors and cabling must be supplied by the user or ordered
from Conair. A converter is available if your controls do not use the standard com-
munications you desire. See Appendix A page A-3 for the proper cabling and con-
nection information for both types of interface.
U s i n g t h e M o d b u s Pa r a m e t e r L i s t
The Modbus interface uses standard Modbus protocol to communicate with a com-
mon controls system. The data that may be retrieved is arranged in a parameter list.
By using the Modbus register read and write commands, the desired data may be
read from or written to the controller. The list of data that may be set or retrieved
with the common controls system is arranged in Modbus registers 500 to 539.
See Appendix A page A-1 for the data contained in this area for your particular
type of equipment. DC-2 control parameters are used on a dryer with a DC-2 con-
trol panel and DC plus control parameters are used with Hopper Temperature
Controllers (HTC) or ResinWorks.
A - 2 l M o d b u s C o m m u n i c a t i o n s