MULTICHANNEL SYSTEMS USB-ME128-System, Системное руководство

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Troubleshooting
15
5.2.5 Rear Panel
5.2.6 Digital In / Out
A
Digital IN / OUT
for 16 digital in- and output bits is available (68-pin MCS standard connector). The
Digital IN / OUT connection accepts or generates standard TTL signals. TTL stands for Transistor-Transistor
Logic. A TTL pulse is defined as a digital signal for communication between two devices. A voltage between
0 V and 0.8 V is considered as a logical state of 0 (LOW), and a voltage between 2 V and 5 V means 1
(HIGH).
The Digital OUT allows generating a digital signal with up to 16 bits and read it out, for example by
using a Signal Divider SD16 from MCS. You can utilize this digital signal to control and synchronize
other devices with the USB-ME128 . Bit 0 of the Digital OUT is separated and available as Lemo connector
DIG OUT D0. So if you need only one bit of the digital signal, you don’t need the additional signal divider
SD16. Please read chapter "Pin Layout" (Digital IN / OUT Connector) in the Appendix for more information.
The Digital IN can be used to record additional information from external devices as a 16-bit encoded
number. The Digital IN is most often used to trigger recordings with a TTL signal from a stimulator.
Therefore, the bits 0 and 1 of the Digital IN are accessible as the Lemo connectors on the front panel
as Digital Trigger Inputs 0 and 1.
The 16 digital input channels are represented as the digital data stream that is, a stream of 16-bit values,
each bit (0 to 15) representing one digital input. Standard TTL signals are accepted as input signals on the
digital inputs. Unused input bits, which have an undefined state, should be masked in the Trigger Detector
of MC_Rack.
Warning: A voltage that is higher than +5 Volts or lower than 0 Volts, that is, a negative voltage,
applied to the digital input would destroy the electronics. Make sure that you apply only TTL pulses
(0 to 5 V) to the digital inputs.
5.2.7 Digital Output D0
The Bit 0 of the Digital OUT is also accessible independently from the 68-pin Digital IN / OUT connector.
The digital output channel D0 is generally used for synchronizing the
USB-ME128-System with a stimulus
generator, or with another data acquisition system, for example, an imaging or a patch clamp system.
The DIG OUT D0 generates standard TTL pulses.
5.2.8 Synchronization Out- and Input
If you want to use several USB-ME128-Systems in parallel, the SYNC OUT and SYNC IN can be used to
synchronize the individual devices. The SYNC OUT of the first device must be connected to the SYNC IN of
the second, and so on. For the connection you need cable with Lemo plugs on both heads (C-Lemo-Lemo).
Warning: Do not use the SYNC IN and SYNC OUT to connect the
USB-ME128
to any other device
than another USB-ME128.