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ControlLogix 7252 LDT Interface Manual
Revision 1.5
Chapter 5: Setup Data
The message instructions described in chapter 4 above are used to send the setup data to the two channels of the
7252 module. This data consists of seven 32 bit words (28 bytes) shown in the following table. Each channel can
be programmed with different setup data.
Setup Data for the LDT Module
Data
Type
Word
Number
Function
Range
Factory Default
32-bit
0
Configuration Bits
See description below
0
32-bit
1
LDT Gradient
80000 to 99999
90000
(9.0
µ
s/inch)
32-bit
2
Full Scale Length
2 to 800 inches or
50 to 20320 mm
16 inches
32-bit
3
Full Scale Count
2 to (1000 * Length in inches) or
2 * (Length in mm * 10)
16000
32-bit
4
Preset Value
0 to 16# FFFF_FFFF
-2,147,483,648 to +2,147,483,647
0
32-bit
5
Limit Switch ON-Position
0 to 16# FFFF_FFFF
-2,147,483,648 to +2,147,483,647
0
32-bit
6
Limit Switch OFF-Position
0 to 16# FFFF_FFFF
-2,147,483,648 to +2,147,483,647
0
All of the data must be present and valid when the message instruction is used to send the data to the 7252 module. If
the data is not valid, all of the data will be ignored, the message instruction’s error bit will be set, and the extended
error code will indicate exactly how the data is invalid. See chapter 3 for definitions of the set up parameters.
Configuration Bits:
Bits 0 to 7: Reserved, must be 0;
Bit 8: Transducer Fault Latch (0=self clearing, 1 = Latched Fault)
Bit 9: Program Count Direction (0 = Positive, 1 = Negative)
Bit 10: Program Velocity Update (0 = 160ms, 1 = 60ms)
Bit 11: Latch position on rising edge of input
Bit 12: Latch position on falling edge of input
Bit 13: Measurement Units (0=inches, 1=mm)
Bit 14 to 16: LDT Mode
Bit 16
Bit 15
Bit 14
LDT Mode
0
0
0
Start/Stop Mode (default)
0
0
1
Control Pulse Mode
0
1
0
PWM Mode 1
0
1
1
PWM Mode 2
1
0
0
reserved
1
0
1
reserved
1
1
0
reserved
1
1
1
reserved
.Bits 17.. 31: Reserved, must be 0;
Note 1: The Velocity Update Time does not affect the update of the Data Value.
Note 2: Programming a channel’s setup data will clear the internal offset generated by an Apply Preset Operation.
