Benefits and Features
16 digital /O ports
When configured as an input, each port can monitor logic state, count pulses, measure signal frequency, and determine duty cycle
Consumes less than 1 mA power in most applications
Compact package with spring-loaded, vibration-resistant terminals
Connects to the data logger via three ports that can be shared with up to 15 other SDM devices
Multiple different functionfso r programming each input and different function assignments for different ports on the same module
Capability of each terminal to directly drive low-voltage valves orrelays
I/O lines protected against high-level surges with gas discharge tubes

Technical Description
When a port is configured as an input, it can measure the logical state of the port, count pulses, and measure the frequency of—and determine the duty cycle of—signals applied to the port. In pulse-counting mode, there is also an option to enable switch-debounce filtering so the unit can accurately count switch-closure events. The SDM-IO16A measures the frequency of signals by measuring the time between pulses, thereby giving relatively high-resolution measurements even for low-frequency signals.
The module can also be programmed to generate an interrupt signal to the data logger when one or more input signals changes state.
When configured as an output, each port can be set to 0 or 5 V by the data logger. In addition to being able to drive normal logic-level inputs, when an output is set Hl, a "boost" circuit allows direct control of some low-voltage valves and relays. (Referto the Specifications section on the web page.) The SDM-IO16A is a synchronously addressed data logger peripheral. Data logger control ports 1, 2,and 3 are used to address the SDM-I016A and exchange digital data with it. This module uses advanced error-checking techniques to ensure correct transmission of data to and from the module. Up to 16 SDM-I016As may be addressed, making it possible to control a maximum of 256 ports from the first three data logger control ports.