Using External Amplifiers
Use the connectors on top of the controller to access necessary signals to run external amplifiers. For more
information on connecting external amplifiers, see Step A in Chapter 2.
Error Monitoring and Protection
The amplifier is protected against under-voltage and over-current conditions. The controller will monitor the error
conditions and respond as programmed in the application. The errors are monitored via the TA command. TA n
may be used to monitor the errors with n = 0 or 3. The command will return an eight bit number representing
specific conditions. TA0 will return errors with regard to under voltage, and over current. TA3 will return if the ELO
input has been triggered.
The user also has the option to include the special label #AMPERR in their program to handle soft or hard errors.
As long as a program is executing in thread zero and the #AMPERR label is included, when an error is detected the
program will jump to the label and execute the user defined routine. Note that the TA command is a monitoring
function only, and does not generate an error condition.
See the TA command for detailed information on bit status during error conditions.
Over-Current Protection
The stepper driver has circuitry to protect against over-current. If the total current from a set of 2 axes (ie A and B
or C and D) exceeds 10 A, the SDM-44140 will be disabled. The amplifier will not be re-enabled until there is no
longer an over-current draw and then either SH command has been sent or the controller is reset. The amplifier
will never go into this mode during normal operation. The amplifier will be shut down regardless of the setting of
OE, or the presence of the #AMPERR routine.
NOTE
: If this fault occurs, it is indicative of a problem at the system level. An over-current fault is usually due to a
short across the motor leads or a short from a motor lead to ground.
Under-Voltage Protection
If the supply to the amplifier drops below 12 VDC, the amplifier will be disabled. The amplifier will return to
normal operation once the supply is raised above the 12V threshold.
Note
: If there is an #AMPERR routine and the controller is powered before the amplifier, then the #AMPERR
routine will automatically be triggered.
A8 – SDM-44140 (-D4140) ▫ 254
DMC-40x0 User Manual