In parallel operation always make sure to use identical operating voltages and avoid exceeding
voltage and current limits. Small differences in voltage limit circuit can lead to high balancing
currents and can cause the amplifier to shut down.
6 Integration into Automated Test Systems
For integration into automated test systems the commands of the USB interface are described in
the following. The USB interface is installed as a virtual COM port at 9600 baud, 8 data bits, 1 stop
bit and no parity. The command frame consist of a length byte (entire frame) followed by an
address byte. Then there is a command byte and optional parameters. Only command frames
corresponding to its own address will be considered. There is a timeout of 500 ms, that is, if after
500 ms the required number of bytes hasn't been sent, the previous bytes are ignored! The
feedback frame corresponds to the command frame, e.g. length, address, command and optional
parameters. The feedback is always carried out
after
execution of the command! When an
unknown command occurs, the feedback is 0xFE, and with a timeout 0xFD. Several amplifiers can
be driven via a COM interface. In this case, each amplifier requires its own address (1 ... 99, default
= 1), which is determined by a command. The address 100 is answered by all amplifiers regardless
of the stored address.
6.1 List of Remote Commands
●
0x01
Status query, parameters: no; answer: 1 Byte status:
Bit 0: Ready
Bit 1: Overload shutdown power/power loss
Bit 2: Heatsink overtemperature/transformer
Bit 3: Output relay (0: off, 1: on)
Bit 4: 50R-Input relay (0: off, 1: on)
Bit 5: 100k-Input relay (0: off, 1: on)
Bit 6: operating v (0: low, 1: high)
Bit 7: operating voltage – (0: low, 1: high)
●
0x02
Set 50R-Input , Parameter: 1 Byte (0: off, 1: on)
●
0x03
Set 100k-input , Parameter: 1 Byte (0: off, 1: on)
●
0x04
Set Output relay , Parameter: 1 Byte (0: off, 1: on)
●
0x05
Set operating voltage, Parameter: 1 Byte
(0: low, 1: high, 2: only UB+ high, 3: only UB– high)
●
0x06
Query temperature, Parameter: no, answer: 1 Byte temperature in
0
C
●
0x07
Query max. power loss, Parameter: no, answer: 1 Byte
Power loss in % of the current threshold (maximum since last
query)
A1230-02
Integration into Automated Test Systems
Page 22
