12
TMC211 DATASHEET (V. 1.04 / January 7, 2005)
The amount of equivalent full steps during acceleration phase can be computed by the next equation:
2
min2
−
V
max
V
N
step
=
2⋅ Acc
5.1.7 Position Ranges
Position information is coded by using two’s complement format. Depending on the stepping mode
(see 5.1.1) the position ranges are as listed in the following table:
Stepping Mode
Position Range
Full range excursion
Half-stepping
-4096…+4095
(-212…+212-1)
-8192…+8191
(-213…+213-1)
-16384…+16383
(-214…+214-1)
-32768…+32767
(-215…+215-1)
8192 half-steps
213
1/4 micro-stepping
1/8 micro-stepping
1/16 micro-stepping
16384 micro-steps
214
32768 micro-steps
215
65536 micro-steps
216
Table 6: Position Ranges
Target positions can be programmed via LIN interface by using the SetPosition command (see
6.11.11). The actual motor position can be read by the GetActualPos command (see 6.11.1).
5.1.8 Secure Position
In case of emergency (communication loss) or GotoSecurePosition command (6.11.5) the motor
drives to the secure position. The secure position is programmable by the user. Secure position is
coded with 11 bits, therefore the resolution is lower than for normal positioning commands, as shown
in the following table.
Stepping Mode
Half-stepping
1/4 micro stepping
1/8 micro stepping
1/16 micro stepping
Secure Position Resolution
4 half steps
8 micro steps (1/4th)
16 micro steps (1/8th)
32 micro steps (1/16th)
Table 7: Secure Position Resolution
5.1.9 External Switch
Pin SWI will alternately attempt to source and sink current in/from the external switch (Figure 1:
TMC211 Typical Application on page 7). This is to check whether the external switch is open or closed,
resp. if the pin is connected to ground or Vbat. The status of the switch can be read by using the
GetFullStatus or the GetActualPos command. As long as the switch is open, the <ESW> flag is set to
zero.
Copyright © 2004-2005 TRINAMIC Motion Control GmbH & Co. KG
TRINAMIC [ TRINAMIC MOTION CONTROL GMBH & CO. KG. ]
