ADC16 and PGA16: sets of 16 more waveform inputs 2701 -3 and -4
The set of waveform input channels may be expanded by adding an ADC16 (2701-3) expansion box with sixteen extra channels, which are mapped onto ADC channels 8-23. Once the Power1401 is told about the extra channels by the installation program, the new ones may be freely used just like the basic set. Software that reads the extra channels will return undefined data values if the waveform expansion box is not installed.

The ADC inputs are of identical design to the ones on the base unit, with an input range of ±5V (optionally ±10V). As on the base unit, there is an option of programmable gain x1, x2, x5 and x10 for 16 waveform inputs (2701PG) or 8 waveform inputs (2701PG8)

A similar unit, PGA16 (2701-4), is available with individually programmable gain on each channel, in steps of x1, x2, x5, x10 in the range from x1 to x1000.

Spike2 top-box 2701-9
In some circumstances, such as in many Spike2 applications, the digital inputs and outputs are heavily used for signals. It is convenient to have more of these connectors available on the front panel as BNCs. The 2701-9 top-box provides six event inputs, mapped onto digital inputs 10-15, together with eight ADC inputs and a pair of DACs, mapped onto ADC 8-15 and DAC 2-3 respectively. The safe working voltage range of the digital inputs is ±10V, and they present an impedance of 100 kOhm.

Signal top-box 2701-5
The Signal program is often used with many waveform channels. The 2701-5 top-box provides eight more ADC inputs and four more DACs, mapped onto ADC 8-15 and DAC 4-7 respectively, with 2 of the original digital outputs, 2 and 3, and 2 of the DACs all available on BNCs on the front panel.

12 channel event expansions 2501-12
The CED 2501-12 gives Spike2 12 extra event inputs. These new events are sampled using the Spike2 digital marker channel. Each event input generates an 8 bit digital code and the codes are recorded on the digital marker channel. The unit is free standing, with its own separate power supply. If you have this unit fitted, you must enable the digital marker channel, then each event will be recorded as a marker coded from 0 to 11. You can display these as separate channels in Spike2 by duplicating the channel for each event and setting the marker filter for the duplicated channel to show only one event code.

You can stack these units; each unit adds 12 more event channels, suitably coded. The 1401 will unload events from the unit in sequence, taking perhaps 10 microseconds to unload an event. Events are unloaded in priority order with lower numbered event channels having the higher priority. If it is likely that you will have simultaneous events on multiple channels you must consider if the timing uncertainties will limit the number of channels you can use.

8 channels of tracking filter with PLL synthesiser

The PGF8 2701-21 is designed for researchers in vibration analysis and other systems generating periodic signals. It provides eight signal-processing channels plus auxiliary circuits. The heart of each channel is the switched-capacitor filter (SCF) and selectable gain, but there are also options for AC coupling, and simultaneous sample-and-hold (S&H). The channels have individual control of gain level, and individual enabling of the SCF and the AC coupling. The SCF pass frequency and the S&H functions act equally on all channels.

A phase-locked loop (PLL) offers programmable frequency multiplication of a trigger source. This can be very useful when triggering information comes from smoothly-varying systems such as rotating shafts. The front panel provides outputs for DACs 2 and 3.