TMCM-1141 Hardware Manual (Rev. 1.06 / 2015-JAN-09)
17
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4
Motor driver current
The on-board stepper motor driver operates current controlled. The driver current may be programmed in software
in two ranges (low current range up-to 1.1A RMS and high current range up-to 2A RMS) with 32 effective scaling
steps in hardware for each range.
Please note: the high current range is available with hardware revision V1.3, only and should not be activated /
used with hardware revision V1.2! The high current range should not be used with motor currents above 2A RMS
–
this will violate specification of the module - please note limitations at the end of this chapter!
Explanation of different columns in table below:
Motor current
setting in
software (TMCL)
These are the values for TMCL axis parameter 6 (motor run current) and 7 (motor standby
current). They are used to set the run / standby current using the following TMCL
commands:
SAP 6, 0, <value> // set run current
SAP 7, 0, <value> // set standby current
(read-out value with
GAP
instead of
SAP
. Please see separate TMCM-1141 firmware
manual for further information)
Range setting in
software
(TMCL)
This is the value for TMCL axis parameter 179 (Vsense). This value defines the current
range. This value can be set using the following TMCL command:
SAP 179, 0, <value> // = 0 high current range
// = 1 low current range
For
<value>
either 0 (high current range) or 1 (low current range) is supported (see
table) since hardware revision V1.3. For hardware revision V1.2 this parameter should not
be changed to any value other than
“1” (low current range).
(read-out value with
GAP
instead of
SAP
. Please see separate TMCM-1141 firmware
manual for further information)
Motor current
I
RMS
[A]
Resulting motor current based on range and motor current setting
Motor current
setting in
software (TMCL)
Range setting in
software
(TMCL)
Current
scaling step
(CS)
Motor
current
I
COIL_PEAK
[A]
Motor current
I
COIL_RMS
[A]
0..7
1
0
0.052
0.036
8..15
1
1
0.103
0.073
16..23
1
2
0.155
0.109
24..31
1
3
0.206
0.146
32..39
1
4
0.258
0.182
40..47
1
5
0.309
0.219
48..55
1
6
0.361
0.255
56..63
1
7
0.413
0.292
64..71
1
8
0.464
0.328
72..79
1
9
0.516
0.365
80..87
1
10
0.567
0.401
88..95
1
11
0.619
0.438