User and Programming Manual
XDS Series
75
9.6 Trouble Shooting - RS232C
This section provides guidelines for resolving communication problems that may occur when using
the XDSGUI software under Windows
™
.
You may encounter problems when using the serial interface with the XDSGUI program that is
supplied with the interface option for this source.
Symptoms:
1. Unable to verify connection to the power supply through RS232C interface. Time-out occurs and
dialog box appears that asks if you want to switch to simulation mode. An error message (ERR -
100) may appear on the front panel LED’s of the power supply.
- Or -
2. Verification is successful but slewing of voltage or current limit results in an ERR -100.
Things to check first:
1. Is any PC com port available for communication with the power supply? On older PC’s com port
interrupts are often shared between com 1 and com3 as well as com2 and com 4. If any of these
other com ports is in use, it may prevent you from using the com port that shares the same
interrupt.
2. Did you use the RS232C cable that was supplied with the power supply? If not, make sure you
obtain the correct cable. (DB9 to DB9, straight through, male to female).
Resolution for Symptom 1
The XDS Series of power supplies require hardware handshaking to control data flow from the PC to
the Power supply. After receiving a command, the power supply asserts the DTR line to hold off
further communication from the PC until the command just sent has been processed. Under
Windows, it is possible to use a 16 byte transmit buffer if a 16550 UART is present. This FIFO
exceeds the length of most Power supply commands. When enabled, this mode may result in more
than one command being placed in the UART output buffer. If this happens, the handshake from the
Power supply will not prevent the content of this buffer being sent to the Power supply and thus will
result in more than one command being sent to the Power supply.
To resolve this problem, the UART FIFO length needs to be reduced or disabled altogether. The
procedure to disabled the FIFO mode is outlined in the next paragraph.
Note: If turning off the UART FIFO conflicts with other applications that need to run on the same PC
using the same COM port, this solution may not be acceptable. In this case, skip this step and
proceed to the second symptom resolution, which relies on a software implemented hold-off instead
of turning off the FIFO buffer.
Содержание XDS 100-100
Страница 4: ...User and Programming Manual 4 XDS Series Electrical Safety Symbols Used in This Manual ...
Страница 27: ...User and Programming Manual XDS Series 27 Figure 3 5 Outline Drawing XDS DC Supply ...
Страница 41: ...User and Programming Manual XDS Series 41 Figure 5 4 Parallel Cable Interconnect Accessory ...
Страница 45: ...User and Programming Manual XDS Series 45 Figure 6 1 DC Power Supply Block Diagram IF option shown ...
Страница 69: ...User and Programming Manual XDS Series 69 Figure 8 3 Replaceable Fuse Locations ...