Internet PLC Forum

General => Technical support => Topic started by: yosepht on September 17, 2006, 03:40:29 PM

Title: output fault
Post by: yosepht on September 17, 2006, 03:40:29 PM

 Hi!
     I have a T100MD+  and an expansion units that have two output
ports I can't turn off. Output ports2 and 34 are always on. Which one
is the device that controls the outputs that I might need to replace?
or is there any other solution I can try ?
                                                                thanks.

Title: Re:output fault
Post by: support on September 17, 2006, 06:12:54 PM

Please specify the exact PLC model and expansion board since different PLCs and expansion board uses different I/O driver.

Title: Re:output fault
Post by: yosepht on September 18, 2006, 06:07:46 PM

The PLC is T100MD-888+ Rev. D-1
The expansion is MD-EXP4040 Rev. A
 
     That is right of the boards, I hope it is what you need.
                                         
                                                           thanks.

Title: Re:output fault
Post by: support on September 18, 2006, 10:03:15 PM

Digital Output #1 to 4 on T100MD888+ are controlled by the output driver ULN2803A to the right of the output terminal. The IC 74HC595 to the left of the output LED 5-8 is also responsible for driving the status LED and the signal to the ULN2803A and this may need to be changed if the damage to ULN2803A is too severe.

Digital output #34 is controlled by the IC TPIC6A595NE. This is a Texas Instrument part number and is available from some component stockists such as Digikey.com

Title: Re:output fault
Post by: yosepht on September 19, 2006, 08:13:54 AM

   Thanks, I will try to find and replace them.

Title: Re:output fault
Post by: yosepht on September 20, 2006, 03:24:19 PM

   Replacing the ULN2803 cleared output 2. I am stil looking for the other chip
I am sure that will clear as well.
                                                        thank you for your help.