OpenGL FBO Multiple textures -

I have an FB in which I add two textures, then I want to pair the FOO, first texture as input (Bandh) I want to use in a shadar and write on the other texture, both are associated with fibro. I tried to use glDrawBuffer to specify GL_COLOR_ATTACHMENT1 as buffer, but without success Is it possible anyway?

Edit :

How do I try to do this here:

  Glumeux Texx, tex1; // They are made elsewhere and are bound to fbo glBindFramebuffer (GL_FRAMEBUFFER, fbo); GloveWitches (GL_TEXTURE0); GlobIndactations (GL_Edit DD, Texx); GlDrawBuffer (GL_COLOR_ATTACHMENT1); // render code glReadBuffer (GL_COLOR_ATTACHMENT1); GlReadPixels (...);   
 But the result of glReadPixels is different than what I expected. Can you see any problems here?   
 
 
 FBO just like a normal texture, bind it using glBindTestxture.  
 I believe that if you have a pattern for a sample and an FBO, then you get an undefined behavior.