Cooper Bussmann BU-905U-L installation manual Status Outputs, Analog Input

Cooper Bussmann BU-905U-L Wireless I/O Installation Manual

Status Outputs

The unit contains the following status outputs:

•System OK;

•Setpoint Output; and

•Communications Failure.

Status outputs are FET output to common rated at 30Vdc 500mA.

Connect the output circuit to the appropriate Status Output terminal. Each status output circuit is associated with an LED indicator that lights lit when the digital output is active.

The following table details the status output behavior:
Status Output	LED	LED Status	Description
System OK active (both modules)	OK	Green	No fault detected
System OK inactive	OK	Red	• Internal fault detected.
			• Supply voltage Low
			• Analog Loop supply overloaded
Setpoint Output (BU-905U-L-T)	SP	Green	Local setpoint attached to 4-20mA analog input.
Communications Failure (BU-905U-L-R)	CF	Red	Watchdog alarms active on digital outputs or analog outputs.

Analog Input

The BU-905U-L-T module provides one 0-20mA DC analog input for connecting to instrument transducers (e.g. level, moisture, pressure transducers, etc.).

Note: The BU-905U-L-T module inputs measure down to 0mA and can also be used for zero based signals (e.g., 0-10mA).

The analog input has a positive and negative terminal and can be placed at any point in the current loop, providing neither input rises above the 24 volt Analog Loop Supply level.

Each input has a loop resistance of less than 250 ohms and zener diode protection is provided against over-voltage and reverse voltage. Note: You may require additional protection in high voltage or noisy environments or for long wiring runs.

A 24Vdc loop supply is available on the BU-905U-L-T module for powering the analog transducer loops. In this situation, connect the:

•Analog loop - between an Analog Input (-) terminal and Ground.

•Positive terminal – i.e., Analog Input (+) to the +24V Analog Loop Supply.

Externally powered loops may be connected by connecting the input between "Analog Input (+)" and “Analog Input (-)” Common mode voltage may be -0.5V to 27V.

18 www.cooperbussmann.com/BussmannWirelessResources 3A1580Rev1.6