Datasheet

TMC2300 DATASHEET (Rev. 1.02 / 2019-NOV-06) 56
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14.3 Open Load Diagnostics
Interrupted cables are a common cause for systems failing, e.g. when connectors are not firmly
plugged. The TMC2300 detects open load conditions by checking, if it can reach the desired motor coil
current. This way, also undervoltage conditions, high motor velocity settings or short and
overtemperature conditions may cause triggering of the open load flag, and inform the user, that
motor torque may suffer. In motor stand still, open load cannot always be measured, as the coils
might eventually have zero current.
Open load detection is provided for system debugging.
In order to safely detect an interrupted coil connection, read out the open load flags at low or
nominal motor velocity operation, only. A flicker may occur with asymmetric sense resistors and does
not harm. However, the ola and olb flags have just informative character and do not cause any action
of the driver.
14.4 Diagnostic Output
The diagnostic output DIAG provides important status information. An active DIAG output shows that
the driver cannot work normally. The index output signals the microstep counter zero position, to
allow referencing (homing) a drive to a certain current pattern. The function set of the DIAG output
can be modified by UART. Figure 14.1 shows the available signals and control bits.
DIAG
Power-on reset
Toggle upon each step
Short circuit (s2vs, s2g) over temperature (ot)
S
R
Q
drv_err
Power stage disable (e.g. pin EN, STANDBY)
Index pulse
GCONF.diag_index
GCONF.diag_step
MUX
Overtemperature (ot)
StallDetection
(gated by TSTEP<=VCOOLTHRS)
Figure 14.1 DIAG output
UART