Max input voltage and Input impedance of channel C and D


What’s the max input voltage, and the input impedance of the D and C channel ?

Whats the diffrence between A and D channel, for example ? Both are working with a digital signal… (no analoge signal for test…).


1.the max input voltage is 80v with x1 proble and 400v with x10 peoble.
2. analog channel means the inputed signal was sampled with a A/D converter, and then displayed. while digital channel means the input signal was judged by the controller if it is “1”(high level) or “0”(low level).

Thanks for answering.

I’ve experimented a sine wave form on the channel D, and I saw what do you mean… :wink:

Are you sur the maximum input voltage on D and C channel is 80Vpp ?

Thanks !

actully, from the shematic, there is a CESD5V0AP at the input cuicuit of ChC and ChD, that is to say , when the input is <5V , the CTr/DTr will be same as input , when the input>5V, the CTr/DTr would be about 5V. so , maybe you do not need to consider the input range as the ChC and ChD are designed to detect the communication which is not exceed 10 V
and at the same time , the “impedence of channel C and D” is meaningless i think, maybe we can say : inpedance is 90K9 when the voltage <5V. :laughing: