User`s manual

DS2100 User’s Manual SECTION 7: CANOPEN DRIVE PROFILE: DS402
PAGE 7-24 C27750-001
GENERAL ISSUES
1) The current draft of DS402 standard does not list all valid dimension types (e.g. no acceleration units
defined). The following table lists the supported dimensions
Physical Dimension Units Dimension Index Linear / Rotational
Angle/Length/Position m. 0x01 Linear
rad. 0x10 Rotational
sec. 0x43 Rotational
min 0x42 Rotational
deg 0x41 Rotational
revs 0xB4 Rotational
Velocity m/sec 0xA6 Linear
m/min 0xA7 Linear
m/hr 0xA8 Linear
rev/sec 0xA3 Rotational
rev/min 0xA4 Rotational
rev/hr 0xA5 Rotational
Acceleration m/sec
2
0x55 Linear
m/min
2
0xB1 Linear
rev/sec
2
0xAF Rotational
rev/min
2
0xB0 Rotational
Table 7.7 Table of factor dimensions
2) Velocity Encoder Resolution is read only, and set to a fixed value of 65536/1, since internally the velocity
is always scaled to correspond to 65536 increments/rev. DS402 indicates that this parameter should be
writeable.
3) Velocity Factor 1 is incorrect in DS402, since it lists vel units instead of position units in denominator. The
velocity factor 1 is implemented as shown earlier.
4) Acceleration Factor is incorrect in DS402, since it does not include acceleration or velocity notation
indices. The factor is implemented as shown earlier.
5) Sub-Index 2 of the Position Factor is incorrectly listed as Feed Constant, when it should read divisor.
6) A mix of rotational (e.g. rev/sec) and linear units (e.g. m) is not allowed. The position, velocity and
acceleration units must all be either all rotational or all linear. An error is not returned when they are not the
same, since this would prevent them from ever being changed.
7) If the dimensions are rotational, the feed is set to a fixed value (e.g. always 360 degrees per rev), and will
return an error if attempt to set feed when dimension is rotational.
8) When any of the inputs to the factors change, the outputs, and their dependencies are all updated.
9) The output parameters are read only, being set implicitly from the input values, they cannot be explicitly
set.
10) The standard does not explicitly state if rounding should occur, or return an error, when the inputs to the
factor group, cause the output values to exceed the size of fixed point 32-bit numerator or denominator.
Similarly, it doesn’t specify what should happen if scaling a parameter by a factor, could result in an
overflow. What is implemented in both cases is that an error is returned, and a parameter called factor error
is set to indicate the reason for the most recent error. It is recommended that factors be set initially upon
configuration, and not altered subsequently. The table below lists the factors error code values, with the
first 4 indicating errors in setting up the output of the factors group, and the remainder indicating errors,
setting up parameters which depend/use the factors. : -