User manual
Accessory 24E2
Connector and Terminal Description 27
Ixx81 and Ixx91 (Power-On Phase Position Address and Format)
Occasionally the MLDT is used to establish an absolute phase reference position for Turbo-PMAC-
commutated motors. In this case, Ixx81 and Ixx91 are set to the same values as Ixx10 and Ixx95,
respectively (see above).
Pulse Output Frequency
The pulse-output frequency is established by assigning an M-variable to the C sub-channel command
register, and writing a value to that M-variable after every power-up/reset. The suggested M-variable for
the Motor xx using this register is:
Mxx07->Y:{address},8,16,S
where {address} is specified according to the following table:
Mxx07 for Acc-24E2A MLDT Pulse-Output Registers
Servo IC #
Channel 1
Channel 2
Channel 3
Channel 4
2
$078204
$07820C
$078214
$07821C
3
$078304
$07830C
$078314
$07831C
4
$079204
$07920C
$079214
$07921C
5
$079304
$07930C
$079314
$07931C
6
$07A204
$07A20C
$07A214
$07A21C
7
$07A304
$07A30C
$07A314
$07A31C
8
$07B204
$07B20C
$07B214
$07B21C
9
$07B304
$07B30C
$07B314
$07B31C
The frequency of the pulse output should produce a period just slightly longer than the longest expected
response time for the echo pulse. For MLDTs, the response time is approximately 0.35 sec/mm (9
sec/inch). On an MLDT 1500 mm (~60 in) long, the longest response time is approximately 540 sec; a
recommended period between pulse outputs for this device is 600 sec, for a frequency of 1667 Hz.
To produce the desired pulse output frequency, the following formula can be used (assuming a 16-bit M-
variable definition):
)kHz(Freq_PFMCLK
536,65
07Mxx
)kHz(OutputFreq
or:
)kHz(Freq_PFMCLK
)kHz(OutputFreq
*536,65Mxx07
To produce a pulse output frequency of 1.667 kHz with the default PFMCLK frequency of 9.83 MHz,
calculate:
11
380,9
667.1
*536,65Mxx07
To write this value to the register, a power-on PLC routine is suggested; this can also be done with on-
line commands from the host computer. Sample PLC code to do this for Channel 1, using the above
example value, is:
OPEN PLC 1 ; PLC 1 is first program to execute
CLEAR
M107=11 ; Set pulse frequency
CMD”$*” ; Absolute Position Read
DISABLE PLC 1 ; To not execute again
CLOSE