AMETEK ASD Series - Manual (Page 60)

Programming: Digital Interface Control Sorensen ASD Series
4-2 M551177-01 Rev A
 Controlling setpoints
 Programming system shutdowns through selectable faults
 Monitoring load protection
 Controlling external processes
4.2 COMMAND REGISTERS
The power supply has two sets of registers, one for writing setpoints and
configuration (read/write registers) and the other for reading unit and
module status and measurements (read only registers). Each register is
16 bits wide.
4.2.1 READ/WRITE REGISTERS
Operating the power supply through the digital interface involves reading
and writing data to a few important registers.
In the Command write register (address 0x0), enabling of the power
supply’s output is controlled by bit 1 (COMMAND_BIT_ON). Writing a “1”
to this bit enables the output and writing a
“0” disables the output.
In the Voltage, Current and Power write registers (addresses 0x1 – 0x6)
setpoints are controlled and encoded in either 32-bit floating point when
Command bit 7 is “1” or IQ15 fractional notation when Command bit 7 is
“0”. (IQ fractional notation of integer data: IQ15 means that the desired
real value is multiplied by 2
15 , e.g., 0.5 = 16384 in IQ15).
HI R EGISTER AND LO R EGISTER
The voltage, current and power setpoints are 32-bit values and each uses
two registers: HI and LO, where the most significant 16-bits are written to
the HI register, and the least significant 16-bits are written to the LO
register.
Voltage setpoint is programmed by writing data to the Vsetpoint _HI/LO
(addresses 0x1
– 0x2) write registers. In IQ15 this value is normalized so
that 1.0 corresponds to a setpoint of full-scale voltage (60V / 40V). In
floating point no normalization is required when writing the desired voltage
value.
Current setpoint is programmed by writing data to the Isetpoint_HI/LO
write registers (addresses 0x3
– 0x4). In IQ this value normalized so 1.0
corresponds to the full-scale current of one module 167A / 250A. In
floating point no normalization is required when writing the desired current
value.
Power setpoint is programmed by writing data to the Psetpoint_HI/LO
write registers (addresses 0x5
– 0x6) will change the power setpoint. In IQ
this value is normalized so that 1.0 corresponds to the full scale power of