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CMC TECHNICAL REFERENCE MANUAL
1X36003 Version 2.52
1996-1999 Ingersoll-Rand Company
Date of Issue: 18-Oct-1999
A bit response of 1 means that the output is ON and a response of 0 means that the output
is OFF.
Command 0F/Function 67 - PLC5 Typed Write
CAUTION
The position of the REMOTE COMMUNICATIONS DISABLED/ENABLED
selector switch is NOT considered when forcing coils or writing registers to the CMC.
Reads and Writes are always enabled. Repeatedly writing a value to a register or
forcing a coil without regard to the position of the switch can effectively disable a local
write. Please use caution when writing registers or forcing coils.
The CMC is treated as a PLC5 when this command is issued. This command writes data to
the CMC starting at the specified data table address. You can write to a setpoint with either
an integer or floating point number.
Example: Presetting Analog Setpoints for 32-bit Values
To write 105.4 PSIG as a floating point number to the user pressure setpoint (CMC data
table address, 86h), issue the following command:
DLE
STX
DST
SRC
CMD
STS
TNS
FN
C
Packet
Offset
Total
Trans
PLC5 System Address
10
02
0D
11
0F
00
81
CE
67
00
00
01
00
07
00
0B
86
A
B
DLE
ETX
BCC
99
09
06
94
08
CD
CC
D2
42
10
03
93
The response from this command is:
DLE
STX
DST
SRC
CMD
STS
TNS
DLE
ETX
BCC
10
02
11
0D
4F
00
81
CE
10
03
44
The difficulty in setting 32-bit values is determining the four data bytes for the number you
want to send. The process required is ...
1. Determine the sign (positive = 0 or negative = 1). This is the first bit.
2. Divide the decimal value by 2 until the result is less than 2, but greater than 1. Count the
number of iterations required. Add 127 to the number of iterations. This result is the
exponent. Convert this result to binary. These are the next eight bits.
Response (hex)
Bit
7
6
5
4
3
2
1
0
CMC Data
Address
183
182
181
180
179
178
177
176
Byte 1
28
0
0
1
0
1
0
0
0
Bit
15
14
13
12
11
10
9
8
CMC Data
Address
191
190
189
188
187
186
185
184
Byte 2
10
0
0
0
1
0
0
0
0
