Faraday MC - Tony

Check that the 5V power supply is delivering 5V. If if drops to about 4.7V or less you will see problems. If the 5V is low the cause could be external wiring or possibly a problem on the UMAC power supply.

Check your Windows firewall to make sure that DeltaTauGatherProgram is allowed through.

Please note that by default C source code is not downloaded to the PMAC. If you want to be able to upload and open the source you need to change the project properties so that the files are downloaded with the rest of the project.

The current sense firmware in the Brick attempts to null the offsets automatically so you don't normally need to use the PMAC offsets. This only affects the current feedback, not the output. External amplifiers do not always perform the offset measurement automatically so it needs to be done in the PMAC. With a Brick there is nothing to stop you applying the PMAC offsets as well. If you use a negative number for CurrentNullPeriod it has the effect of compensating for the small offsets in the output caused by the switching transistor characteristics. It might not work well for you because it could cause the voice coil to move when the test current is turned on. In that case you could calibrate the system with the stage locked and then use fixed values for IaBias and IbBias.

Hi Leandro, Try setting Motor[x].CurrentNullPeriod to a negative number (try -1000 to start with). It will measure the current with the motor energised and remove any offset caused by the output stage.

Multiple instance of the gather program appeared in my firewall with different capitalisation (see screenshot). I had to allow them all through to get the plot program working correctly. Try manually adding another rule and see if you also find another version with capital letters in the name.

The problem Eric described happens almost every time I forget to click out of the box on my laptop. It makes tuning a frustrating experience because it is very easy to forget. The bug is still present in V4.4.0.99.

Check your 5V power supply. I have seen something similar when the rise time of the 5V was too slow. We were using a DC-DC converter and for us the solution was to use a relay to turn the 5V on after the DC-DC was switched on.

Hi Geoff, I fixed "Control Right Release Error" by changing the DC shift time to half of the cycle time.

If you have a 32 axis Acc5E3 it appears to the PMAC as two cards. It is very easy to set one of the ACC24E3 cards to the same address as the second bank on the 5E3 and it causes the watchdog problem you describe. Make sure that you don't have overlapping addresses.

Coordinate System 1 (&1) Variables M5197->X:$002000,0,24,S ; &1 Host commanded time base (I10 units) M5198->X:$002002,0,24,S ; &1 Present time base (I10 units) They are scaled relative to I10.

Did you remember to set Sys.WpKey=$aaaaaaaa before trying to change the setting in the Gate3?

Messages to the PMAC are terminated with a carriage return. The response from the PMAC depends on the setting of I3. Have a look at the description of I3 in the Turbo PMAC Software Reference Manual for a full description.

You could increase the PWM frequency up to 30khz but I think the recommended 20khz should be sufficient. You need to use a current probe and an oscilloscope to see if there is a problem with current ripple.

Hi Matheus, You have already discovered that it is not easy to configure small motors on big amplifiers! It is possible to do it but it requires care. We have many customers who have made it work. I suggest putting a fuse in each phase to provide protection if you have an incorrect setting. Start with a very small value for Motor[x].Iigain. Try 0.01 and a current step of 100 bits and see what happens. Make sure that the current loop is controlling properly without a massive overshoot. I know all the units you have are 5/15A versions but there are also smaller versions (0.25/0.75 and 1/3) available if you need to run a lot of small motors. Tony Jacobs (Faraday Motion Controls)