Ingersoll-Rand CENTAC, Technical Reference Manual

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96
CMC TECHNICAL REFERENCE MANUAL
1X36003 Version 2.52

1996-1999 Ingersoll-Rand Company
Date of Issue: 18-Oct-1999
Signed
16 Bit Exponent
Unsigned
16 Bit Fraction
Signed
IEEE 32-Bit Float
Holding Register Name - Read/Write
Absolute
Address
(Decimal)
Relative
Address
(hex)
Absolute
Address
(Decimal)
Relative
Address
(hex)
Absolute
Address
(Decimal)
Relative
Address
(hex)
Inlet Valve, MaxLoad, Proportional Constant 40313 01-38 40314 01-39 43313 0C-F0
Inlet Valve, MaxLoad, Integral Constant 40315 01-3A 40316 01-3B 43315 0C-F2
Inlet Valve, MaxLoad, Derivative Constant 40317 01-3C 40318 01-3D 43317 0C-F4
Inlet Valve, MinLoad, Proportional Constant 40319 01-3E 40320 01-3F 43319 0C-F6
Inlet Valve, MinLoad, Integral Constant 40321 01-40 40322 01-41 43321 0C-F8
Inlet Valve, MinLoad, Derivative Constant 40323 01-42 40324 01-43 43323 0C-FA
Inlet Valve, Pressure, Proportional Constant 40325 01-44 40326 01-45 43325 0C-FC
Inlet Valve, Pressure, Integral Constant 40327 01-46 40328 01-47 43327 0C-FE
Inlet Valve, Pressure, Derivative Constant 40329 01-48 40330 01-49 43329 0D-00
Bypass Valve, Pressure, Proportional Constant 40331 01-4A 40332 01-4B 43331 0D-02
Bypass Valve, Pressure, Integral Constant 40333 01-4C 40334 01-4D 43333 0D-04
Bypass Valve, Pressure, Derivative Constant 40335 01-4E 40336 01-4F 43335 0D-06
Compressor Control Mode; 1=Modulate, 2=Autodual 40339 01-52 40340 01-53 43339 0D-0A
NOTE : (J1-P1) is interpreted as Connector J1, Pin 1 on the Base Control Module.
Example: See example for Function 04.
Function 04 - Read Input Registers
Reads the binary content of input registers (MODBUS 3x references) in the slave (CMC
Base Control Module). For the CMC, these input registers refer to the Analog Input values.
Broadcast is not supported.
The CMC is primarily a 32-bit floating-point microprocessor controller. And, since MODBUS
is designed to be a 16-bit system, the CMC supports two methods for determining the value
for each holding register. (This also applies to Input Registers.) The first method uses two
16-bit integers to represent the integer and fraction part of the value. The second method
uses one 32-bit IEEE floating point number.
NOTE
Since MODBUS is a 16-bit system, the programmer must get two 16-bit numbers and
combine them into one 32-bit floating-point number.
For those who would like to only get the 16-bit integer value, this will work well for most
inputs; however, the CMC has some inputs, like vibration, that are typically less than one.