Multichannel Systems MEA2100-System Manual - Manual (Page 50)

MEA2100-System Manual
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6.3
Triggering / Digital Input does not Work
You have connected a TTL source to one of the digital inputs of the MEA2100-System,
and configured the virtual rack in MC_Rack for triggering displays or data acquisition
by the TTL source, but you do not see any sweeps.
Possible causes:
? The TTL source does not generate true TTL signals (> 1.5 to 5 V TTL level), or the TTL pulse
duration is too short in combination with the sampling rate, so that the pulse is missed in-
between two data points.
The MEA2100-System can only accept TTL signals as a digital input stream. The TTL pulse
needs to be optimized according to the sampling rate. Otherwise, a detection of the trigger
cannot be guaranteed.
? The software settings for the Trigger Detector do not match with the hardware configuration.
In MC_Rack, add a Trigger Detector to your virtual rack, and select the Digital Data D1 input
stream as the Trigger. Check the pin layout of the Digital IN / OUT connector and make sure that
the same bit input that is connected is selected in the software. (The standard settings of the
Trigger Detector are for using bit 0.) Mask all unused bits. Select the appropriate logical state
(generally HIGH) for triggering. Please see the MC_Rack help or manual for more details.
6.4
Noise on Single Electrodes
The noise level on single electrodes is significantly higher than expected or you see artifact signals.
Possible causes:
? The electrode or the contact pin of the headstage may be defective. To test this, do the
following.
Open the amplifier and turn the MEA by 90 degrees. Close the MEA2100 headstage again
and start the recording.
If the same electrode in the MEA layout is affected, the amplifier's contact is not okay.
If another electrode is now affected and the previously affected electrode is all right now,
the MEA electrode is not okay, but the headstage is fine.
— OR —
Use the test model probe to test the MEA2100 headstage. If the noise level is fine without
the MEA, bad MEA electrodes cannot be the cause.