APS 6RL Series, Operation Manual

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6RL SERIES OPERATION MANUAL
SECTION 7: REMOTE PROGRAMMING
Entire Contents Copyright
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2018 by Adaptive Power Systems, Inc. (APS) • All Rights Reserved • No reproduction without written authorization from APS.
6RL Series Regenerative DC Load Operation Manual Page 135 of 204
7.11.7.2 Programming example for the arbitrary generator
Before you can configure the arbitrary generator for a ramp, it is necessary to think about
the best way to achieve the ramp generation. It is important to keep in mind that the
arbitrary generator stops at the end of the function run, unless you set the repetition to
infinite. After a stop, the DC Input remains switched on. In case of a ramp, this is wanted,
because the end value shall usually remain set for time x. However, the unit will go to static
mode again, setting the static set values of U, I and P. The static values also apply for the
period before the function run and for situations when the DC Input is already switched on.
The stop action and the static values are thus a little problematic for the ramp function.
Why? Supposed, you wanted to have a DC load generate a ramp starting from 0 V. The static
value for U (voltage) would then be set to 0. However, after the function stop, the unit
would also set 0 V and the voltage would drop from whatever value has been set during the
function run. Conclusion: the static value of voltage has to be part of the function.
In order to achieve this, the function has to consist of two parts: one for the rising or falling
ramp and the other for the static value. This can be done using two sequences of the
arbitrary generator.
Assumption: you have a load and the ramp shall start from 0 V and rise to 50 V within 6
seconds. The end voltage shall remain constant for 3 minutes (the time can be varied at
will). Sequences 1 and 2 will be used. Remote control is already active, we only need to
configure the sequences. Since the ramp will make the voltage rise linearly, using only the
DC part of a sequence, the parameters for the AC part (indexes 0 - 4) should be set to zero in
order to avoid remainders which could disturb the correct wave generation.
The first step is to activate function generator mode, in this case we select arbitrary
generator for U:
Addr FC Start Data CRC
0x00 0x05 0x0353 0xFF00 0x7DBE
Next step is to create the ModBus message to configure sequence 1, the rising ramp.
According to the register list start register 900 (WMR, function code 0x10) is assigned to
sequence 1. Because the data part would not fit the width of this document's page size, the
8 float values are below each other:
Addr FC Start Regs Bytes Data CRC Description
0x00 0x10 0x0384 0x10 0x20 0x00000000 Start value of AC part: 0 V
0x00000000 End value of AC part: 0 V
0x00000000 Start frequency of AC part: 0 Hz
0x00000000 End frequency of AC part: 0 Hz
0x00000000 Start angle of AC part: 0°
0x00000000 Start value of DC part: 0V
0x42480000 Start value of DC part: 50V
0x4ab71b00 0x5A14 Rise time in μs: 6,000,000 (6 seconds)