Manufacturer: Rockwell Automation
Brand: Alan Bradley
Part Number/Catalog number: Model 1756-OF4
Series: ControlLogix
Output: 4 current-voltage
Module type: analog output module
The Allen-Bradley 1756-OF4 module is a ControlLogix non-isolated output module. It has four voltage or current outputs with a current resolution of 15 bits (current current with a current resolution of 21 mA and current current with a current current of 650 nA/ bit) and a voltage resolution of 16 bits (10.5V, 320 μV/ bit). It requires a 20-pin RTB or detachable terminal housing to connect field devices. Compatible RTBS are 1756-TBSH and 1756-TBNH. Before installing the module to the chassis and power supply using RTB, ensure that the chassis and power supply are installed and grounded.
The output module has a data scroll timestamp, power off Remove and insert (RIUP), onboard functionality, module resolution, producer/consumer communication, and multiple data formats. The data formats available for this module are floating-point mode and integer mode. The module can also use channel data to multicast fault data and status to the owner listening controller.
The 1756-OF4 module backplane has a rated voltage and current of 5.1V DC and a maximum rated voltage and current of 150 mA for 24V DC. It has a current consumption of 150 mah at 5.1V and 120 mah at 24V, with a total backplane power of 5.8W. Its power consumption is 3.7W backplane power and overvoltage protection is 24V DC. The open circuit detection of the module is only applicable to the current output, but the output should be set to greater than 0.1 mA. It also has short-circuit protection with a limit of 21 mah or less.
The output range is 0 to 20 mah, with 0 mah and -32768 counts for signals and users, and 21.2916 mah and 32767 counts for high signals and users, respectively. In the +/ -10V output range, the module has low signal and user numbers of -10.4336V and -32768, and high signal and user numbers of 10.4336V and 32676, respectively. It performs a 2-second routine test at 1350V AC and has a continuous isolation voltage of 250V,
The module has a voltage drive capability greater than 2000 ohms and a current drive capability of 0 to 750 ohms. It has a module scan time of 12 ms floating point, a scan time of 8 ms integer, and a module error of 0.15% of the voltage range and 0.3% of the current range. Under resistance load, its establishment time is less than 2 ms to 95% of the final value.
The Allen-Bradley 1756-OF4 is an analog output module capable of providing analog voltage and current signals. These output signals can be used to drive modulation devices and actuators, or to retransmit signals for use by loggers, indicators, data loggers and external controllers.
The module has an output voltage signal of +/ 10 VDC or 4-20 mA, and a resolution of 15 bits (10.5V, 320 μV/ bit) and 15 bits (21 mA, 650 nA/ bit). Using R-Ladder DAC, the monotonicity of the no-loss-code conversion method is adopted. When configuring floating point, the module scan time is 12 ms, and the integer is 8 ms.
Analog output modules are commonly used to modulate actuators and devices such as variable frequency drivers (VFDS), modulated control valves, dampers, shutters, and other actuators. It is usually designed to implement control outputs or commands configured in a user program. Such a user Pro version of gram might include proportional-integral-differential (PID) controllers, mathematical calculations, manual input interfaces, Move, and similar analog processing instructions.
Analog outputs are also available for loggers, indicators and data loggers. It can also be used to connect external controllers as remote set points to be part of more advanced control strategies, such as cascades, feed-forward, and others that use more than two (2) process variables.
The module needs to be calibrated every 12 months with a calibration accuracy better than the 0.05% range, ranging from 4 to 21 mA and -10.4 to 10.4V.
