24
07 = Not used.
08, 09 = Hardware fault. Return to Factory for service.
10 = Undefined command. Command not within acceptable range.
SPI Protocol
The Society of the Plastics Industry (SPI) communication protocol specifies
a connection management Protocol, a packetized communication format,
and communication error mechanisms passing commands and data
between a host computer and a slave. A host computer initiates all
communications. The protocol used corresponds to the 3.01 version of the
SPI communication protocol specification dated October, 1990. The data is
transmitted via a multidrop EIA-485 (half-duplex) hookup. The character
format required is 1 start bit, 8 data bits, no parity and 1 stop bit.
The M2B controller will support a number of commands that will allow the
host computer to retrieve status and assign set points. The commands
correspond to a mold temperature controller device.
Commands
Descriptions
(CMDl) (CMD2)
(20H)
(20H)
Echo poll —
Controller integrity command. Return the 4 bytes of ASCII
assigned by the Echo Select command in an open format.
(21H)
Echo Select —
Controller integrity command. Supplies 4 bytes of ASCII in
an open format that is to be returned when an Echo Poll command is
received.
(22H)
Version poll —
Returns a version number (AABB
=
0101) as 4 bytes of ASCII
in an open format where:
AA = SPI assigned version level
BB = Vendor assigned version level
(30H)
Set point poll —
Returns the current process set point value in numeric
format.
(31H)
Set point select —
Assigns a value to the process set point in numeric
format.
(32H)
Alarm, high temperature deviation poll —Return the high temperature
deviation set point value in numeric format. This value when added to the
process set point gives the temperature at which a high alarm will occur.
(33H)
Alarm, high temperature deviation select —Assigns a value to the high
temperature deviation set point in numeric format.
(34H)
Alarm, low temperature deviation poll —Returns the low temperature
deviation set point value in numeric format. This value when subtracted
from the process set point gives the temperature at which a low alarm will
occur.
(40H)
Status process poll —Returns the status of the process as 16 flag bits in
open format. The following bits are supported. The rest are set to 0.
Bit 0 —
Processing
Bit 1 —
Alarm, System
Bit 2 —
Alarm, Process
Summary of Contents for M2B
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