SERVICE
23
MAGNET POWER SUPPLY SYSTEM 8500
The SW will after the start (Trig) command update the output current every 1.25m. sec in the FAST
and in the SLOW mode (Step Time). This enables it to calculate the stair case size (interpolating step
size) according to the formulae below:
Where “START” and “END” are the set values in ppm., The “Step Time” is 1.25m. Seconds,
Ä
t
in seconds and the “Step. Size” will come out as ppm. value.
In-between the 1.25ms step time a second HW interpolation counter will update the set value for
every 78
ì
s (fast ramp times) to about 78
ì
s (slow ramp times).
Starting the ramp is done with the trig command “TS (stack no.)”.
If synchronisation to an eternal event is required, it is possible to arm the ramp sequence first with
the synchronisation command “SYNC (stack no.), [trigger delay]”. A hardware signal on the trigger
input P33 pin 1&2 (10 to 24V) or a TS command will start the sequence. If a trig delay is entered,
the sequence will first start after the delay time has elapsed.
If more power supplies have to be synchronized, one of the supplies has to be appointed as master.
Connecting the master trig output P33 pin 3&4 to the other supplies trig input will start the other
supplies when the master is triggered. A maximum skew of 5
ì
s between the supplies may be
expected. (an external 15V auxiliary supply is needed, as the trig output is an open collector and the
trig input is an opto coupler input.)
3.3.4.2. Equal time slot ramp profile method.
With the”Equal time slot method” it is possible to download up to 1000 current set values and a
single time slot value, that will be used for all set values. Only one stack is available.
This profile method is specially useful for faster and more accurate curves fitting profiles e.g. as an
function generator.
To use the Equal time slot method at least the following steps must be performed:
- Clear and set the stack “RAMPSET [parameter]”,- Program the stack “R [parameter]”, -Start
the stack “RAMP [parameter]”, -Read the status of the running stack “RAMP".
PS.
A difference in the value parameter setting compared to the “Arbitrary point method” is, that
all values must be given as a floating point number scaled to “1.000000". That is; 1.25ms must
be entered as 0.00125 and 19.54% output current as 0.1954.
Please refer to the Appendix 2 “SW2 Ramp Profile Commands” for full instructions.
DANFYSIK A/S - DK 2630 TAASTRUP - DENMARK.
DOC NO P80303Sk