Master - Slave flash Sigma vs Canon

I have a Sigma 500 DG super, and a Canon 420 EX. I tried to ise them as master-slave. I use the Sigma as a master with a connecting cord and the Canon as slave.
The results I have are very poor it semms that the Sigma is not managing the Canon's output.
Does enybody know if these 2 flashes can work together or not ?
Anyone using the same configuration ?

Yes, they work together. Why are you using a cord at all? Make sure the channels are set to the same frequency. If I recall correct, the 420EX uses letters while the Sigma uses numbers. A=1, B=2, etc. Also make sure the IR (red box) on each unit can "see" each other. When the 420EX is in slave mode I think the IR should be blinking.

Oh, yeah the Sigam should be set with ETTL with two lightening bolts. One indicates that the master (Sigma) will fire and the other means it is sending the signal to the slave (420EX).

The owner's manual for the Sigma is horrible and it takes time to figure it out.

Ditto for Canon 420EX.

---Bob Gross---

I'm using the cord because the soe of the sigma is broken and do not stay in the camera shoe.
The question is that the 420 do fire, but it seems that the power is not manaed by the master. Maybe because of the broken shoe it does not make the proper connections.

I just confirmed with Sigma. While using Sigma 610 Super as Master and Canon as a Slave, E-TTL metering will not work from canon flash. Flash will fire but without any calibration for Canon slave.

Which cord are you using? You say that the foot of the Sigma is broken? If you are using a traditional PC cord, E-TTL will not work. The only signal that goes down that cord is the signal to fire. You would need to operate the flash manually. For E-TTL to work, you have to use the E-TTL cord that has the 5 pins on it and they need to conduct electricity to the 5 pins on the foot of the flash. That's how the E-TTL signal is communicated.