Description
The 1746SC-INO4I is a high-performance, four-channel analog output module engineered by Spectrum Controls for the Allen-Bradley SLC 500 platform. This module is specifically designed for current-only applications (0-20 mA or 4-20 mA) where electrical noise, ground loops, or differing potentials between field devices could compromise signal accuracy. The 'I' designation confirms individual channel-to-channel isolation, ensuring that a fault or noise on one loop does not propagate to other outputs or the backplane.
Features
-
Individual Channel Isolation: Provides 500V AC continuous isolation between each channel and the backplane, preventing ground loops.
-
High Precision: Features 16-bit resolution for accurate control of VFDs, proportional valves, and other current-driven actuators.
-
Current Output: Supports 0-20 mA, 4-20 mA, and 0-21 mA sourcing ranges.
-
Fast Response: 1 ms step response time to 95% of full scale.
-
Flexible Powering: Supports external 24V DC power to minimize backplane current draw.
Applications
This module is ideal for industrial control environments requiring high signal integrity, such as:
- Variable Frequency Drive (VFD) speed control.
- Proportional valve positioning.
- Process control loops where electrical isolation is required to prevent cross-channel interference.
- Systems with high electromagnetic interference (EMI) or common-mode voltage challenges.
Technical Specifications
| Model |
1746SC-INO4I |
| Manufacturer |
Spectrum Controls (for SLC 500) |
| Number of Outputs |
4 |
| Output Type |
Current Only (Sourcing) |
| Current Ranges |
0-20 mA, 4-20 mA, 0-21 mA |
| Resolution |
16-bit |
| Step Response |
1 ms (to 95% of full scale) |
| Backplane Current |
120 mA @ 5V DC / 250 mA @ 24V DC |
| Isolation Voltage |
500V AC continuous |
| Thermal Dissipation |
5.0 Watts (Max) |
| Operating Temperature |
0 to 60 degC (32 to 140 degF) |
Installation Guidelines
-
ESD Precautions: Always handle the module by the edges and use a grounded wrist strap to prevent electrostatic discharge damage to internal components.
-
Power Down: Ensure the SLC 500 chassis power is disconnected before installing or removing the module.
-
Wiring: Use shielded twisted-pair cable for all analog signals to minimize noise. Ground the shield at one end only, typically at the signal source or the module common, depending on system requirements.
-
Isolation: Ensure that external power supplies used for the 24V DC loop power are properly rated and isolated to maintain the integrity of the channel isolation.
-
Ventilation: Maintain adequate clearance around the SLC 500 chassis to ensure proper airflow and heat dissipation within the specified operating temperature range.
FAQ
Does this module require external power?
The 1746SC-INO4I can be powered via the backplane, but it supports external 24V DC power to reduce the load on the SLC 500 chassis power supply.
Is this module compatible with standard SLC 500 racks?
Yes, it is designed as a drop-in replacement or addition for the Allen-Bradley SLC 500 I/O platform, utilizing the standard 1746 backplane interface.