Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Synchronizing Turbo PMAC to External Events
359
For PMAC2-style Servo ICs, the M-variable definitions for the position-capture flags are shown in the
following table. With the standard assignment of channels to motors, the suggested M-variable for the
flag for Motor xx is Mxx17.
following table. With the standard assignment of channels to motors, the suggested M-variable for the
flag for Motor xx is Mxx17.
Servo IC #
Channel 1
Channel 2
Channel 3
Channel 4
0 X:$078000,11 X:$078008,11 X:$078010,11 X:$078018,11
1 X:$078100,11 X:$078108,11 X:$078110,11 X:$078118,11
2 X:$078200,11 X:$078208,11 X:$078210,11 X:$078218,11
3 X:$078300,11 X:$078308,11 X:$078310,11 X:$078318,11
4 X:$079000,11 X:$079008,11 X:$079010,11 X:$079018,11
5 X:$079100,11 X:$079108,11 X:$079110,11 X:$079118,11
6 X:$07A200,11
1 X:$078100,11 X:$078108,11 X:$078110,11 X:$078118,11
2 X:$078200,11 X:$078208,11 X:$078210,11 X:$078218,11
3 X:$078300,11 X:$078308,11 X:$078310,11 X:$078318,11
4 X:$079000,11 X:$079008,11 X:$079010,11 X:$079018,11
5 X:$079100,11 X:$079108,11 X:$079110,11 X:$079118,11
6 X:$07A200,11
X:$07A208,11
X:$07A210,11
X:$07A218,11
7 X:$07A300,11
X:$07A308,11
X:$07A310,11
X:$07A318,11
8 X:$07B200,11 X:$07B208,11 X:$07B210,11 X:$07B218,11
9 X:$07B300,11 X:$07B308,11 X:$07B310,11 X:$07B318,11
9 X:$07B300,11 X:$07B308,11 X:$07B310,11 X:$07B318,11
Bit 10 of the same status word on PMAC2-style Servo ICs also is set to 1 if the most recent position
capture used the encoder’s index (Bit 0 of I7mn2 = 1) gated to a single quadrature state wide (I7mn4 = 1).
This indicates that the captured position is suitable for use to see if the proper number of counts have
elapsed since the previous gated-index capture, a good safety check for encoder count loss.
capture used the encoder’s index (Bit 0 of I7mn2 = 1) gated to a single quadrature state wide (I7mn4 = 1).
This indicates that the captured position is suitable for use to see if the proper number of counts have
elapsed since the previous gated-index capture, a good safety check for encoder count loss.
Whole-Count Position-Capture Register
The position-capture register for an encoder channel contains the value of the encoder counter at the time
when the last trigger condition occurred. It is a 24-bit register, in units of counts, usually treated as a
signed quantity. The suggested M-variable for this register is Mxx03 for Motor xx (with encoders
assigned to motors in the standard order).
The position-capture register for an encoder channel contains the value of the encoder counter at the time
when the last trigger condition occurred. It is a 24-bit register, in units of counts, usually treated as a
signed quantity. The suggested M-variable for this register is Mxx03 for Motor xx (with encoders
assigned to motors in the standard order).
A count here is a hardware count that is, one increment of the hardware encoder counter. This is often,
but not necessarily, the same as a software count, what the motor software considers a count. In the case
of digital quadrature feedback where the motor gets feedback position with 5 bits of estimated or
measured fraction – 1/32 of a count – hardware and software counts will be the same.
but not necessarily, the same as a software count, what the motor software considers a count. In the case
of digital quadrature feedback where the motor gets feedback position with 5 bits of estimated or
measured fraction – 1/32 of a count – hardware and software counts will be the same.
However, in some cases, as with high-resolution interpolation of a sinusoidal encoder through an Acc-51,
where 10 bits of fraction are calculated per hardware count, the resolution of hardware counts and
software counts will be different. In the case of Acc-51 position, a hardware count will be equivalent to
32 software counts.
where 10 bits of fraction are calculated per hardware count, the resolution of hardware counts and
software counts will be different. In the case of Acc-51 position, a hardware count will be equivalent to
32 software counts.
For PMAC-style Servo ICs, the M-variable definitions for the position-capture registers are shown in the
following table. Note that the capture register is read-only; a write operation to the same address is a
write to the position-compare register for the channel.
following table. Note that the capture register is read-only; a write operation to the same address is a
write to the position-compare register for the channel.
Servo IC #
Channel 1
Channel 2
Channel 3
Channel 4
0 X:$078003,0,24,S
X:$078007,0,24,S
X:$07800B,0,24,S
X:$07800F,0,24,S
1 X:$078103,0,24,S
X:$078107,0,24,S
X:$07810B,0,24,S
X:$07810F,0,24,S
2 X:$078203,0,24,S
X:$078207,0,24,S
X:$07820B,0,24,S
X:$07820F,0,24,S
3 X:$078303,0,24,S
X:$078307,0,24,S
X:$07830B,0,24,S
X:$07830F,0,24,S
4 X:$079003,0,24,S
X:$079007,0,24,S
X:$07900B,0,24,S
X:$07900F,0,24,S
5 X:$079103,0,24,S
X:$079107,0,24,S
X:$07910B,0,24,S
X:$07910F,0,24,S
6 X:$07A203,0,24,S
X:$07A207,0,24,S
X:$07A20B,0,24,S
X:$07A20F,0,24,S
7 X:$07A303,0,24,S
X:$07A307,0,24,S
X:$07A30B,0,24,S
X:$07A30F,0,24,S
8 X:$07B203,0,24,S
X:$07B207,0,24,S
X:$07B20B,0,24,S
X:$07B20F,0,24,S
9 X:$07B303,0,24,S
X:$07B307,0,24,S
X:$07B30B,0,24,S
X:$07B30F,0,24,S