Instruction: Generate an answer to the question by utilizing the information contained in the document.

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Question: How do you make ST-E2 talk with 430 EX II on a Canon 6D?  Thanks.
Document: Using the ST-E2 has been a very frustrating experience, the unit managed to fire off my EX 520 II speedlights half the time in a studio situation. Shooting outside with the unit was horrible! I am so disappointed in this product. Do yourself a huge favor and buy some radio triggers! I really hate this thing. I just ordered Aputure Trigmaster Plus Kit from Amazon, this has got to be better then the ST-E2.
I bought the speedlite wireless transmitter and have been using it indoors exclusively. It works great with my Canon 430 EX, even when the reflector blocks the line of sight path.My only complaint is the battery. It cost nine dollars. It will last a long time, but I would prefer that a more common (Cheaper) battery was called for instead.
The unit works well. I have a two speed lights, a 580 and a 430 EX and after using controller I think it would have been money better spend to buy third speedlight and use the 580 EX as the controller. The Canon Speedlight STE2 controls two groups of flashes, A & B. The 580 EX will control groups A, B & C.
I have been wanting to jump in to flash photography a bit more. I had first started by using an off camera flash cord and it didn't fit my needs as I just couldn't put the flash where I wanted to put it the most. As I only have one flash unit,Canon Speedlite 430EX II Flash. I intend to add another one and aCanon Speedlite 580EX II Flashin the near future. And this amazing item will make this all possible. I highly recommend this to anyone starting with off camera flash photography.
This tramsmitter attachment will control them ALL... at once if you so choose. Very handy gadget which has performed perfectly in every test I have thrown at it thus far.My only suggestion to the manufacturers, would be for them to re-release this item with the new quick-lock feature found on the 580EX-II Speedlite flash. :)~I tried it out with Gary Fong's flash diffusers and it was amazing how much they enhanced my portraitures using the ST-E2.
The ST-E2 Speedlite Transmitter is a wireless controller and trigger of compatible EX series Speedlites. The ST-E2 also sports a powerful near infrared AF assist light, a welcome feature for EOS cameras lacking an AF assist light. The ST-E2 should be used with an E-TTL capable camera and Speedlite for best results.APPEARANCE: The ST-E2 is small and light, weighing in at 100 g. The power source, a 2CR5 lithium battery, is light compared to AA batteries.
The limitation of this set-up with 1 580 EX II and a 580 EX is that it is line of sight out to about 50 feet indoors. With strategically placed mirrors you can fire the slaves around corners or opaque umbrellas. I would have preferred Radio Poppers, but they are still not in production on the new version. If you need camera control over the flash, for now this is the only way you cn go.
Various reviews online were mostly mixed in regards to its wireless transmitter function and build quality... but reviews were more unanimous that it was NOT AS GOOD as the Canon ST-E2 in regards to AF Assist (my primary reason of purchase). Because of that, this was not a viable option for me.Is this extra AF Assist functionality worth this extra premium?
I purchased the Canon Speedlite Transmitter ST-E2 and I received it as promised. However, the battery to operate the devise was not included, eventhough Amazon.com description of the item shows that the battery is included. PLease send me this battery as soon as possibe, since I need it for my photography shoot.[... ]Thank you, BajesYou still did not respond about the missing battery.Where is it??? ?
I just purchase this speedlite transmitter ST-E2 and also purchase 3 batteries Im setting up for my first  real wedding getting paid kinda gig. I did my first test indoor with my wife using 2 canon 430ex flash its a wow factor respond . I felt more confident the speedlite did not fail not once and the outcome its great.
Answer: Hi Paul, I have the 6D and the 430EX II as well. To get them talking, you will need to put the flash into Slave mode. This is accomplished by pressing and holding the ZOOM key. You will see an icon of a flashgun with a zig-zag below it. If you press the ZOOM key repeatedly until the CH or SLAVE settings blink, you can use the +/- keys to change the channel and firing group of this flash. To take it out of Slave mode, just press and hold the ZOOM button again.