The Allen-Bradley 1746-NO8I is an Analog Output module capable of producing Current signal ranging from 0 to 21 mA. This module belongs to the SLC 500 controller platform that features Two (2) system varieties - modular style and fixed hardware.

The Fixed hardware is equivalent to compact Programmable Logic Controller (PLC) ideal for use in small applications with limited expansion capability. The modular style hardware is a fully modular, customizable and scalable hardware ideal for use in medium to large applications. The 1746-NO8I are both compatible to these SLC 500 varieties. Especially for installation to a modular style hardware, the 1746-NO8I may be installed to the local or expansion or remote I/O rack. In a local chassis, the module can be installed to any slot except slot 0 as it reserved for the CPU. For expansion rack, the 1746-NO8I is compatible to any slot while if used with a remote I/O rack, the 1746-NO8I cannot be installed in slot 0 as it is reserve for the SLC communication adapter such as RIO, DH+ and Ethernet. Additionally, major considerations when installing this module are ambient temperature and exposure to electrical noise. This module generates a significant amount of heat which makes it ideal to install the module to the chassis nearest to the bottom of the enclosure this is for the reason that cool air goes down and climate control components are commonly installed at the bottom. To minimize electrical noise, install the module away from the system power supply and away from AC line and high DC voltage levels.

This module is capable of detecting module faults such as 24V power failure, Open current loop, Module/SLC resetting and Fatal channel error. These errors are reported to the main controller’s diagnostic buffer.

The Allen-Bradley 1746-NO8I is an SLC 500 module that features Eight (8) analog Current outputs. It is specially designed to be connected to actuators and instruments that execute control in modulating manner. It may be powered by an external 24VDC supply or through the power available in the backplane. This is set using the provided DIP switch. The maximum backplane current consumption of the 1746-NO8I is 120 mA at 5 Volts DC and 250 mA at 24 Volts DC. Before installing the jumper, all system power must be turned off. This includes chassis power and the external 24 Volt DC power supply if there is one.

This module has a thermal dissipation of 6.6 Watts. The maximum wire size of this module is 14 to 24 AWG wire per terminal. The output range of this module is 0 to 21.5 mA. The output coding (proportional scaling) of this module is from 0 to 32,767. The output D/A converter resolution of this module is 16-bit with a 366 nA/count. The output step response time of the 1746-NO8I is 1 millisecond. The output impedance of this module is greater than a 1M ohm. The operating temperature of the 1746-NO8I is -13 to 140 degrees Fahrenheit and the nonoperating temperature is -40 to 185 degrees Fahrenheit.