rigol ds1054z, only 500 Msa/s when only 1 channel active, is it normal ?

[blandiant]

Hi,
i just got a rigol ds1054z with all the options.
When all the channel are turned off, it is writen on the screen that the sample rate is 1 Gsa/s and the memory depth is 24Mpts but as soon as i activate one channel(no matter which one) it is written that the sample rate is 500Msa/s and the memory depth is 12Mpts, and i can't use a higher sample rate/memory depth than this.
Is it normal ? (i attach 2 pictures to show you)

Thank you

[Mechatrommer]

yes its normal when your trigger channel is not the one shown.

[Zero999]

It's because it achieves 1Gsa/s by interleaving multiple ADCs (I can't remember how many, look it up if you're interested) with a lower bandwidth. With only one channel activated, all the ADCs become allocated to that single channel, so the sample rate can be higher, than with two channels activated. I can't remember whether activating three or more channels limits the sample rate even further, but someone else here will know.

[Mechatrommer]

I can't remember whether activating three or more channels limits the sample rate even further, but someone else here will know.

yes, any active channels, including triggering channel, even if not visible, more than 2 = 250MS/s

[Adrian_Arg.]

1 active channel 1 Gsa / s
2 active channels 500 Msa / s
with 3 and 4 activated channels 250 Mgs / s

I do not know if it influences that I have it released as a DS1104Z

[Zero999]

I can't remember whether activating three or more channels limits the sample rate even further, but someone else here will know.

yes, any active channels, including triggering channel, even if not visible, more than 2 = 250MS/s

Right, so there are four ADCs, each capable of 250Msa/s, which can be interleaved to get 1Gsa/s, 500Msa/s or 250Msa/s, depending on whether one, two or three or more channels are required.