AMETEK 1746 LDT Interface Card - Manual (Page 14)

Chapter 3: Set-Up & Programming
Installation & Programming Manual 10
Parameters 4 and 5 are the same as 2 and 3 only they define the LDT and input types for the
second channel (optional). The default configuration is no input.
Command 2: Position Scaling Data
This command will program the LDT characteristics. The parameters for this command have
been defined below:
Parameter 1 indicates which LDT is being used.
Parameter 2 sets the speed of wire. The speed of wire is an integer number to the nanoseconds/
in. The default value for the speed of wire is 9000.
Parameter 3 determines whether the position is moving toward or away from the LDT head.
A zero in this parameter indicates decreasing position and a one in this parameter indicates
increasing position. The default setting is increased.
Parameter 4 contains the number of recirculations the LDT is configured for. The minimum
number of recirculations is 1. The maximum number of recirculations is 64. The default value is
1.
Parameter 5 contains the LDT length to the tenth of an inch. For example, if the LDT length
is 12 inches, the parameter would be 120. This is required only for the VPI LDT and is used to
detect a loss of magnet. The default value is 999.9 inches.
A Save Configuration Command will save these values to non-volatile memory.
NOTE: The EEPROM on the 1746L is only guaranteed to 10,000 write cycles. Because of
this it is recommended that this command be used sparingly.
Command 3: Home Positioning Data
This command resets the position of the LDT specified. The parameters for this command have
been defined as follows:
Parameter 3 is the input type.
Input Type Number Description
0 No Input
1 Movement Detection
2 Position Hold
Output Image Table Description
Word 0 Bit Register
Word 1 Command Register (2)
Word 2 Parameter 1 LDT Number
Word 3 Parameter 2 Speed of Wire
Word 4 Parameter 3 Count Direction
Word 5 Parameter 4 Recirculations
Word 6 Parameter 5 LDT Length (VPI only)
Word 7 Parameter 6 Reserved