Description Of Spi Communications - Conair MDCW Carousel Plus W15 User Manual

D - 2 l S P I C o m m u n i c a t i o n s
D e s c r i p t i o n o f S P I C o m m u n i c a t i o n s
The Society of Plastics Industry (SPI) has defined a standard protocol to be used
for interconnecting plastics equipment. This protocol uses the RS-485 standard as
the physical connection and defines stand addresses and commands to communi-
cate with the various kinds of equipment in common use at a typical plastics facili-
ty. For example, a dryer is specified as Device ID 22 hex, a chiller is Device ID 21
hex. The data retrieved for each type of equipment is defined in the standard. For a
dryer or other piece of equipment to be in compliance with the SPI standard you
must be able to retrieve certain parameters such as the setpoint process tempera-
ture, high and low temperature deviation alarms, temperature to the process, tem-
perature to the process, etc. Some parameters are also designated as optional
parameters that may or may not be available depending on the equipment
provider's discretion.
I n s t a l l i n g t h e S P I C o m m u n i c a t i o n
H a r d w a r e
The SPI option is available with the DC-2 display boards. The display boards have
a RS-232 port built into the board. The RS-232 to RS-485 converters are provided
and mount on the inside of the door of the electrical cabinet. The RS-485 SPI sig-
nal is then brought to the outside of the cabinet by a 9 pin D-sub connector. Refer
to Conair drawing 130024 and 188629 in Appendix A for details of the installa-
tion. The RS-485 SPI signal is available on pins 4 and 5 of the DB-9 connector.
Pins 8 and 9 also have the RS-485 connection (parallel with pins 4 and 5) to assist
in daisy-chaining equipment together.
C o n f i g u r i n g t h e S P I C o m m u n i c a t i o n
S o f t w a r e
The SPI protocol option must be turned on and configured in the operator display
before it may be used.
To setup the SPI communications:
1
Enter the supervisory level password (0210). See your dryer manual for
directions if necessary.
(continued)