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PZ2 Tech Notes

Noisy channel on PZ amplifier at 50kHz sampling rate

TN0903

Product: PZ2, PZ3
Version: Serial numbers PZ2 < 4000, PZ3 < 2000
Date Added: 2012-08-03

Issue

In some cases, user may see low amplitude high frequency noise on the 15th channel of a PZ2 amplifier board (8th channel of a PZ3 board) when running at 50kHz sampling rate.

Solution

It is recommended that users who are operating at 50kHz contact TDT to request an RMA.

Building a custom headstage to use with PZ, IZ, or ACO

TN0896

Product: PZ5, PZ2, PZ3, IZ2, IZ2H, IZ2M, IZ2MH, ACO32, ACO64
Version: All
Date Added: 2012-02-08

Issue

This tech note provides the information needed to wire a custom or third-party headstage to TDT amplifiers, stimulus isolators, and commutators.

Solution

The PZ5, PZ2, PZ3, IZ2, IZ2H, IZ2M, IZ2MH, ACO32, and ACO64 all use the same female mini-DB26 connectors. The mating male connector is made by TE Connectivity (previously Tyco), part number 5749621-2, and can be purchased from Newark, Digikey, or similar vendors. The part number for the connector's backshell kit is 749608-2.

The PZ5, PZ2, PZ3, IZ2, and IZ2H are all battery powered. To conserve power, each bank of channels will not turn on unless a headstage is connected. The device detects whether a headstage is connected through the HSD (HeadStage Detect) pins: pins 18 and 19. These pins should be shorted together on the headstage connector. If pins 18 and 19 are not shorted the headstage will not be detected and the bank that it is connected to will power off.

Important

This does not apply to the IZ2M and IZ2MH. In those devices all banks are always powered.

The pins on the headstage should be made to match the connector on the intended device. The pinouts for each device are shown below.

Note

The user must increment the channel numbers by 16 (or 8) according to the amp, mode and position of the connector. So, for the connector labeled 'A', A1 is channel 1 while on the connector labeled 'B', A1 may be channel 17.

PZ5 Connector Pinout for Building Headstages

PZ5 NeuroDigitizers have up to eight 26-pin headstage connectors on the back of the unit. The connectors are labeled alphabetically from bottom to top. Each connector carries signal for one bank of channels with ground and reference. The corresponding channel numbers depend on:

  1. the reference mode configurations

  2. the position of the bank in a logical amplifier.

For simplicity sake, the diagrams below assume channels for that connector begin with channel 1. For example, A1 - A16 represent the 16 channels coming from the connected headstage.

Local Mode

None Mode

Shared Mode

Differential Mode

PZ2 Connector Pinout for Building Headstages

PZ3 Connector Pinout for Building Headstages

IZ2, IZ2M, IZ2MH Connector Pinout for Building Headstages

IZ2H Connector Pinout for Building Headstages

The ACO passes signals from each header to the pins on the associated DB26 connector on the face of the commutator. The unused pins should not be connected. The pins on the headstage should be made to map to the connected amplifier/stimulator via the header as follows:

ACO Headers - Pinout for Building Active Headstages

For PZ2 or PZ5

For PZ3

ACO Headers - Pinout for Building Passive Headstages

For IZ2, IZ2M, or IZ2MH

For IZ2H

PZ2/PZ3 Signal inversion

TN0868

Product: PZ2, PZ3
Version: PZ2-32:1006-1010, PZ2-64:2018-2025, PZ2-128:2020-2026, PZ2-256:2009-2010, PZ3 < 2000
Date Added: 2009-12-07

Issue

PZ2s and PZ3s with the above serial numbers will generate inverted signal outputs.

Workaround

Place an MCScale component with a SF of '-1' into your circuit to invert the data like the example shown below.

Solution

If you experience this issue contact TDT and request an RMA.

Channel 256 on the PZ2-256 Preamp records erroneous data

TN0855

Product: RZ2, PZ2
Version: All
Date Added: 2009-06-02

Issue

Channel 256 on the PZ2-256 Preamp does not record correctly. The channel appears grounded or shows erroneous data.

Solution

This solution involves a reprogramming of the RZ2 firmware. If you experienced this problem, contact TDT to request an RMA.

PZ2-128, PZ2-256 preamplifiers show up as PZ2-64 in RZ2 LCD display

TN0243

Product: PZ2, RZ2
Version: All
Date Added: 2007-02-28

Issue

The PZ2-128 and PZ2-256 model preamplifiers will show up as PZ2-64 in the RZ2 front panel LED display if there is not a signal source connected to the first connector in the extended channel range. This issue effects the RZ2 display only, not the actual acquisition of signals.

Solution

To display the preamplifier correctly, make sure a signal source is connected to the first channels not available on the lower model number PZ2. For example, a PZ2-128 will show up as a PZ2-64 unless there is a signal source connected to the connector labeled 65-80.

Alternating banks of channels missing when BioAmp operated at 50 kHz

TN0224

Product: PZ2
Version: Serial numbers < 1010
Date Added: 2006-10-17

Issue

When using the PZ2 preamplifier at the 50K sample rate while also using the data pipe module in RPvdsEx every other bank of 16 channel will be read as zero.

Workaround

An immediate work-around to this is to use the MCAdcIn, multi-channel ADC, in RPvdsEx. This will use more processor resources but will read in all the data.

Solution

If you experience this problem you can contact TDT to request an RMA.