An Ethernet data logger for use in common data acquisition applications is the TCW220. It features two discrete inputs and two 10-bit-resolution analog inputs. Up to eight Teracom 1-Wire sensors, including those for carbon dioxide, 0/20 mA, AC/DC current, temperature, humidity, etc., are supported by a 1-Wire interface. Two relays with typically open and normally closed contacts are further included in the Ethernet data logger.
All monitored metrics have the option of being recorded for a previous time frame or in response to an alarm. The memory can store records for every minute for at least 36 days. On a dedicated server, the log file can be routinely posted via HTTP Post.
Periodically, an XML/JSON file containing all monitored parameters can be uploaded via HTTP Post to the dedicated server. For example, an answer server may return instructions for relay control. This is how a SCADA system is built.
The relays can be turned on locally based on the state of monitored parameters or remotely (via WEB, SNMP, HTTP, MODBUS TCP/IP, etc.). Up to five recipients can receive emails and SNMP traps for each parameter. Additionally, an HTTP post containing XML or JSON status files can send an alarm alert.