Elevating Lab Electrical Stimulation Precision: Introducing the New Digitimer SPP-400 Digital Trigger Generator
- Digitimer North America
- Jun 12
- 4 min read
In electrophysiology, neuroscience, and life science research, timing isn’t just an important variable—it is everything. Whether you are stimulating a peripheral nerve, triggering a Transcranial Magnetic Stimulation (TMS) coil, or driving localized LED hardware, the accuracy and repeatability of your trigger source dictate the integrity of your data.
For years, researchers have relied on dependable analog tools like the Digitimer DG2A Train/Delay Generator. But as experimental designs become more intricate, the limitations of manual dials and single-channel hardware can create a bottleneck.
To bridge the gap between simple manual trigger boxes and complex, expensive software-controlled DAQ systems, we are thrilled to introduce the Digitimer SPP-400 Digital Trigger Generator.
The Evolution of Precision: Dialing Out the Guesswork
One of the core limitations of traditional analog train/delay generators, such as our DG2A, is the reliance on physical dials. Precisely setting timing parameters via manual potentiometers can introduce minor variances, and if settings are changed between experimental trials, returning the dials to their exact previous positions is an ongoing challenge. This human error can directly impact your between-trial experimental reproducibility.
The SPP-400 fundamentally changes this workflow by adopting a fully digital architecture. With completely digital controls, operators can precisely and reproducibly set the exact parameters they need down to microsecond resolutions.
Furthermore, the addition of an on-board Protocol Manager allows you to save and store up to eight preset configurations directly to the unit. This ensures that your most critical, commonly used protocols can be recalled instantly with absolute fidelity. Looking forward, we also aim to supply the SPP-400 with a Windows-compatible virtual front panel GUI that will replicate the front panel display and controls, further enhancing ease of use directly from your lab PC.
Versatile Triggering: Edge, Gate, and Toggle Modes
The SPP-400 features a highly adaptable input BNC socket, allowing external laboratory devices to either initiate a protocol of defined duration or start and stop output pulses in response to a voltage input. To accommodate almost any experimental rig, the SPP-400 offers three distinct input mode options:
Triggered Mode: The output protocol initiates instantly on either the rising or falling edge of a brief incoming trigger pulse (such as a digital pulse from a DAQ device). To ensure compatibility with various equipment types, the voltage threshold is fully adjustable between -10V and +10V.
Gated On/Off Mode: The output remains actively driving pulses only while its BNC input receives a voltage that exceeds the user-defined threshold set on the SPP-400.
Trigger On, Trigger Off Mode: This setting acts as a toggle, switching the state of the output protocol on or off with successive incoming trigger pulses.
In addition to the BNC input, a physical manual trigger button on the front panel can be used to test or deploy each of these three modes. For researchers utilizing external hardware like foot pedals or hand switches, the SPP-400 incorporates an optional "de-bounce" control. This software filtration prevents accidental multiple triggers caused by the microscopic mechanical bouncing inherent in contact closure switches.
Link Channels or Use Them Independently
The inclusion of a second output channel massively enhances the capabilities of the SPP-400 over a single-channel analog device. The SPP-400 is capable of operating in multiple standard modes—including Free Run, Gated, Single, or Train—but the dual-channel design unlocks entirely new protocol architectures:
Replicating the DG2A (Delayed Pulses): In its most basic role, Channel 2 can be configured to insert a second, precisely delayed pulse after each pulse generated by Channel 1, seamlessly replicating the delay settings provided by the original DG2A.
Isolated Independent Operation: Both channels can be used in total isolation. A single external BNC input or manual button press can simultaneously trigger two separate laboratory devices with completely distinct timing characteristics, based entirely on the individual settings of Channel 1 and Channel 2.
Linked Channel Operation (Repeating Bursts): By linking the input of Channel 2 to the output of Channel 1, the SPP-400 can deliver highly complex, repeating trains or bursts of pulses. Users maintain granular control over train/pulse frequency, train/pulse number, pulse duration, delay, and even an adjustable output voltage (0V to +10V).
This sophisticated level of multi-burst protocol generation was previously only possible by cascading a pair of independent DG2A units together or utilizing our comprehensive modular NeuroLog System.
Is the SPP-400 Right For Your Lab?
The SPP-400 is not built to replace a massive data acquisition setup, but rather to serve as a fast, highly precise, standalone command center right on your workbench. It is fully compatible with Digitimer’s industry-standard range of isolated electrical stimulators (such as the DS2A, DS3, and DS8R) or any device accepting standard TTL inputs.
If your current research demands tighter control over timing parameters, multi-channel flexibility, or a guarantee of absolute between-trial reproducibility, the SPP-400 is a necessary upgrade to your workflow.
Ready to see the SPP-400 in action? Watch our quick product overview video here to view the digital interface setup, or contact our technical team today to request a quote or discuss evaluating a unit in your laboratory.