Troubleshoot Remote Communication Issues with 85xx

Q: How come my 8500 does not communicate with my computer?

A: There are several things that you can verify and check for.

Before checking the below steps, please be sure you are using the provided IT-E131 or the IT-E132 adapter cable. Do not use a regular serial cable to connect between the instrument and the PC.  This will fail to communicate because the instrument uses TTL level signals, not RS232.

1.  Please check the baudrate, address, parity, and connection mode from the DC load configuration menu.  This can be done by going into menu from the front panel of the instrument (press shift + 0). Go into the "Config" menu, and scroll with the rotary knob or arrow keys to find these 4 selections.  Please note that you have to press "enter" after you make any changes within each settings. If you change the settings without pressing "enter", the settings will not be stored and saved into the memory of the load.   2.  Select the baudrate you want to use.  The default is 9600.  Remember this baudrate because you will use the same in the software either with the PV8500 software or your own software application interface.  3.  Be sure to check the address to be 0, or if you have multiple units, make sure each unit has a different address so you can reference to it based on address in PV8500 or your software application. 4.  Check the parity to be "none".  This is the default.  Do not change if you are using the PV8500 software. 5.  "Connect Mode" is a setting within the configuration menu.  Check to make sure it shows "separate  " on the display.  If not, change it, and press "enter" to confirm your changed setting. 6.  In the PV8500 software, go to configuration, and remember to use the same baudrate and address settings as you configured inside the DC load configuration menu.  They have to match in order for communication to be successful. 7.  If nothing seems to respond, please also be sure to no other software is currently using the COM port that you've selected. Sometimes, an opened or unopened software may have opened the port without closing it properly, making it not accessible by any other software or interface.

Note:  If you are using the IT-E132 USB adapter cable, please be sure to note that the adapter installs a driver and behaves as a virtual COM port.  Windows will automatically assign a COM port to the USB adapter. That is the COM port that will be used for communication. To find out, go to "device manager" of your Windows system and check the "port" list under COM & LPT to verify which COM ports it's been assigned.  it will be labeled as a "USB to serial" device.

The instrument uses a TTL signal level via the serial interface.It does not use RS232. Therefore, you cannot use a RS232 to USB adapter in conjunction with the IT-E131 adapter or with a direct connection from the rear serial interface to the PC.  For USB, you must use the IT-E132 adapter cable.

In some cases, the signal line settings, if set incorrectly, will also cause communication issues. If you are able to successfully communicate with the PV8500 software, but cannot with your own software interface, please check your DTR, RTS.  Both DTR and RTS states should be ENABLED.