KEPCO KLR Series User Manual - Manual (Page 75)

KLR091313
3-35
FIGURE 3-13. LIMIT MODEL DIALOG BOX
3.4 REMOTE PROGRAMMING USING ANALOG SIGNALS
Vref and Cref, present at the Analog Port (see J2, Figure 2-2 and Table 2-7) are the respective
voltage and current programming inputs, used for programming the power supply output in pro-
portion to either and analog voltage drive signal or programming resistance. Normally inactive,
these two inputs are activated by connecting the ANALOG_CTRL pin of J2 to one of the four
GND pins before switching the power supply on. Once the power supply start-up sequence is
completed, the status display reads aRem. The default full-scale voltage level of both Vref and
Cref is 10V; each parameter can be set independently to accommodate lower full scale inputs
(see PAR 3.2.17.5).
While the status display reads aRem (Analog Remote mode), the local output controls are
locked out and digital programming commands are ignored. However, local displays remain
functional and digital queries related to status and readback will be accepted and executed. In
addition, the analog port provides analog readback outputs corresponding to output voltage and
current via the signals VOLT R_BACK and CURR R_BACK, respectively. These outputs are
active at all times and do not require the unit to be operating in Analog Remote mode. The
default full-scale voltage level of both VOLT R_BACK and CURR R_BACK is 10V; Similar to
Vref, and Cref, the readback signal can be set independently to produce lower full-scale outputs
(see PAR 3.2.17.4).
Analog programming inputs are updated once every 0.5 seconds (2 Hz). The default full-scale
programming and readback levels for both voltage and current are 10V. Since Vref and Cref are
converted to digital form, then processed by the digital processing circuitry of KLR (the same as
any other programming input), optimum (12-bit) resolution is achieved when 10V programming
input is equivalent to full scale. It is important to note that the full scale programming input
levels of Vref and Cref correspond to the active limit model setting of the power supply.
Thus, if KLR 75-32 is programmed as a limit model 50V and 20A, applying the full scale pro-
gramming input to Vref and Cref will program the output for 50V and 20A, respectively. One ben-
efit of this feature is the preservation of full 12-bit programming resolution for limit model
settings that are less than the model maximum ratings (Vmax and Imax) as long as 10V analog
input is equivalent to full scale. While the full-scale voltage and readback levels can be reduced
by the user to accommodate system requirements, decreasing the full scale values will result in
degraded programming resolution.