Your welcome, I don't think it is in the spec. You should be able to detect TTL no problem, you just put your voltage trigger level at the appropriate level.
Hi,
The 4227 specs indicate for the Ext Trigger that
- Voltage range ±20 V
- Threshold range ±150 mV to ±20 V
Based on previous discussion in this thread, with a 10bit ADC, one would expect 40mV granularity for the trigger level.
What does the +/- 150mV " threshold range " indicate then? Aren' t the two figures in contradiction?
Thx.
L.
Hi you have a point, my initial post I forgot to mention that there is a +/-150mV threshold where the trigger does not work. This is just due to hysteresis in the circuitry.
Thx Ziko for the clarification, it is helpful, and did not cause trouble.
Still on the triggering topic with a 4224 or 4227 :
- if I want to acquire on Channel 1, and trigger out of channel 2 ( or vice versa), can the range of the triggering channel be set differently than the other channel's (acquisition channel in this example), or do I only set the range of the acquisition channel, the trigger channel range being set internally according to the trigger level ?
- if I want to acquire on Channel 1, and trigger out of channel 2 ( or vice versa), are both channels being acquired, and as a result potientialy (4227) halving my max sampling freq ?
It depends on what you want to do, you can trigger and acquire the data on one channel and that way you can have the maximum sampling rate. If however you wanted to acquire on one channel and trigger on another channel then you need to enable both channels, this way you can have two different voltage ranges one for you acquisition and one for your triggering. The maximum sampling rate will drop the more channels you enable.