Can I guarantee that my Sealevel Digital I/O TTL adapter outputs always power on at zero volts?

Yes, many of our TTL products can be modified to always power on with an off-state of zero volts (TTL “low”). All of our standard TTL adapters are designed for interfacing to industry-standard relay racks that expect an off-state of 5V (TTL “high”). This power on behavior is explained further in the FAQ, Why does my Sealevel Digital I/O TTL adapter have 5 volts present after system power on?

Contact our technical support staff for details on how to order this modification.
This modification is supported on the following TTL devices: