Output Problems

[nikmast 0]

Hi. I am new using plc in general. I have S7 - 200 DC/DC/DC. I downloaded a program on my plc and the program works. What program does is that it makes square wave. While my light bulb is flashing, as it is suppose to my output shows no signs (dead). The program is: Network 1 //10 ms timer T33 times out after (100 x 10 ms = 1 s) //M0.0 pulse is too fast to monitor with Status view. LDN M0.0 TON T33, +100 Network 2 //Comparison becomes true at a rate that is visible with //Status view. Turn on Q0.0 after (40 x 10 ms = 0.4 s), //for a 40% OFF/60% ON waveform. LDW>= T33, +40 = Q0.0 Network 3 //T33 (bit) pulse too fast to monitor with Status view. //Reset the timer through M0.0 after the //(100 x 10 ms = 1 s) period. LD T33 = M0.0

[Crossbow 295]

Code looks valid to me. Do you really need your output off for .4 seconds and on for .6? If you could use .5 on and .5 off there is a system bit already designed for that. Check the manual or the software help files for a list of system bits.

[lazy 0]

I take it when you say your bulb is lighting you are talking about the output l.e.d on the PLC, which would indicate that your code is correct. I think this could be a wiring problem. On the top row of terminals, the output terminals, there are terminals marked 1L,M,2L,M etc. These need to be connected to the 24Vdc power supply that you are powering up the PLC with.

[khekd 2]

If the LEDs are flashing on but your outputs are working it could be the wiring or your device that you have hooked up to the outputs are not able to switch fast enough. The proper wiring of the ouputs can be found in the S7-200 System manual which you can purchase from your local Siemens distributor or may be downloaded here s7-200 system manual