maximal voltage for the additional analog channels

Hi,

I am using a 60 channel USB-MEA system. I am planning to use one of the four additional analog input channels to record voltage signals generated by a stimulator, but I have no idea what the maximal voltage (through these 4 additional analog input channels) the amplifier can bear. Would you please give me some information on this? I am worrying If I use too high voltage the MEA amplifier might be destroyed. Thanks.

Dear sjweng,

the analog input signals are not amplified, but they are just digitalized in the connected DAQ. Please check the input range of your data acquisition device in MC_Rack with connected hardware. Typically you should see a range of about +/- 4V, however it may varie depending on your device connected.

Greetings

Thomas

Thanks, Thomas. I've checked the input voltage range in MC_Rack. Your are right: it is -4096 to +4096 mV.

Another question is that, if I connect a TTL (5 V) output to one of the analog inputs, and run the TTL device, will this damage the system?

-SJWeng

No problem, you will just be clipping the signal
Thomas

Forgive my wordiness --- So it will be fine even if I am running the TTL device for a long time (e.g. the input voltage is at +5 V for tens of seconds, not just transiently) when it is connected to one of the analog inputs instead of a digital input port? I just want do make sure about this, because in the "(USB-) MEA-Systems Manual", I find such words:

...You could also use the analog inputs for triggering the MC_Card or the USB device, but please note that the digital inputs are intended for accepting TTL pulses...

Thanks!

Sjweng

Dear Sjweng,
Thomas is travelling today. Applying 5V for an extended period of time to the Analog In won't damage the system. I don't know how a trigger detector set on this channel will behave, though. Just give it a try.

Best regards Frank MCS

Thank you, Frank & Thomas. Now I am totally relieved. I have tried - The analog in can work as a trigger channel quite well when I connect a 5V TTL output to it: no damage, and I can use the TTL signal to trigger the recording. That's FanTasTic!

SJweng