CMC TECHNICAL REFERENCE MANUAL
1X36003 Version 2.52
1996-1999 Ingersoll-Rand Company
Date of Issue: 18-Oct-1999
99
Determine the sign (positive = 0 or negative = 1) ...
Sign = (R1HB And 128) / 128, where And is defined as a bit-wise And
Sign = (66 And 128) / 128 = 0
Determine the exponent ...
Exponent = ((R1HB And 127)
∗
2) + INT(R1LB / 128), where INT is defined as INTEGER
Exponent = ((66 And 127)
∗
2) + INT(220/128) = 133
Determine the mantissa...
Mantissa = ((((R1LB And 127)
∗
256) + R2HB)
∗
256) + R2LB
Mantissa = ((((220 And 127)
∗
256) + 212)
∗
256) + 198 = 6083782
Putting the 32 bit IEEE value together...
Value = (-1
sign
)
∗
(2
(exponent - 127)
)
∗
((Mantissa
∗
2
-23
) + 1)
Value = (-1
0
)
∗
(2
(133- 127)
)
∗
((6083782
∗
2
-23
) + 1) = 110.4155731201
NOTE
When Sign = Exponent = Mantissa = 0, Value = 0. This is a special case for the above
equation.
Example: Read Multiple Channels
The procedure for reading multiple channels is the same as reading a single channel with
the exception of requesting more data.
NOTE
: You must read a contiguous group of
registers (channels) for a single command.
Function 05 - Force Single Coil
Forces a single coil (MODBUS 0x references) to either ON or OFF. When broadcast, the
function forces the same coil reference in all attached slaves. Refer to the table below for
MODBUS Absolute Addresses for each coil supported by the CMC-MODBUS Interface.
NOTE
This function will override the CMC’s current state. The forced state will remain valid
until the CMC next solves the coil. The coil will remain forced if it is not programmed in
the CMC logic.
