The 1790-T8BV8BX belongs to the CompactBlock LDX product line from Allen‑Bradley. Manufacturers use this digital expansion module to handle mixed input and output tasks efficiently. It accepts 24V DC signals on eight universal inputs. Additionally, it provides eight digital outputs also rated at 24V DC. Each output channel delivers up to 0.5 A. Users can monitor every point through eight green LEDs for inputs and another eight for outputs. The D‑shell connector allows quick connection to a base module or network adapter. Its compact design saves space on a DIN rail. Therefore, this module works well for machine control, packaging lines, and material handling systems.
The 1790-T8BV8BX offers eight non‑isolated inputs. These points can be configured as sinking or sourcing. Minimum on‑state voltage is 9.6V DC, nominal is 24V DC, and maximum reaches 28.8V DC. Off‑state voltage stays below 5V DC. Each input draws typical current of 8 mA at 28.8V DC. Input impedance is nominally 4.8 kΩ. The common type uses eight points sharing one common (non‑polarity). Eight green LEDs light up when the corresponding input is active.
On the output side, the module provides eight non‑isolated sourcing outputs. On‑state voltage ranges from 10V DC min to 28.8V DC max, with 24V DC nominal. The maximum on‑state voltage drop is only 0.5V DC. Minimum on‑state current per channel is 1 mA. Off‑state leakage stays below 0.5 mA. Output signal delay from off to on is 0.5 ms max; from on to off it is 1.0 ms max. Each output can handle 0.5 A continuously, and the common can carry up to 4.0 A total. Eight green LEDs indicate output status.
The base module requires DeviceNet™ power at 24V DC nominal, with an acceptable range of 11…28.8V DC. Maximum power dissipation is 1.2 W at 28.8V DC. Field power also needs 24V DC nominal (10…28.8V DC range). Each point dissipates up to 6 mA at 28.8V DC. Isolation between I/O and logic uses photocoupler isolation rated at 1250V AC rms. Note that DeviceNet™ to logic and DeviceNet™ power are non‑isolated.
This module weighs only 0.38 lbs (0.17 kg). Its housing is rated for industrial environments. Operating temperature range is 0…55°C (32…131°F). Storage temperature goes from -40…85°C (-40…185°F). Relative humidity can be 5…95% non‑condensing. Vibration resistance meets IEC 60068‑2‑6 (5 g at 10…500 Hz). Shock rating is 30 g. The wire terminal uses M3.0 screws with a torque spec of 7 lb‑in max. Use only copper or copper‑clad aluminum conductors.
First, mount the base module on a standard DIN rail. Next, connect the DeviceNet™ cable to the base. Then, slide the 1790-T8BV8BX expansion module onto the interlocking side rails. Press firmly until the D‑shell connector fully mates. Secure the module with the built-in latch. After that, wire field devices to the removable terminal block. Apply torque as specified. Finally, apply 24V DC field power and DeviceNet™ power. The green LEDs should illuminate. Remember to turn off all power before wiring or removing modules.
1 x 1790-T8BV8BX digital expansion module
1 x Removable terminal block (M3.0 screws)
1 x Product label with serial number
1 x Quick start guide (paper)
Note: No certificates or warranty documents are included. Certificates can be downloaded from the manufacturer’s website.
All orders ship via FedEx, UPS, or DHL depending on destination. A tracking number is provided within 24 hours after dispatch.
1. Can the 1790-T8BV8BX work with a DeviceNet™ scanner from another brand?
It is designed for Allen‑Bradley CompactBlock LDX systems. For reliable operation, pair it with a compatible Allen‑Bradley DeviceNet™ master or adapter.
2. What happens if I exceed 0.5 A per output?
Exceeding 0.5 A may trigger thermal shutdown or permanently damage the output channel. Therefore, always limit each output to the rated current.
3. Do the inputs support both PNP and NPN sensors?
Yes. The eight universal inputs can be wired as sinking (PNP) or sourcing (NPN). This flexibility simplifies integration with different sensor types.
4. How do I check if the module is receiving field power?
Look at the green status LEDs. If no LED is lit even when inputs or outputs are active, check the 24V DC field power supply and the terminal block connection.
5. Is the 1790-T8BV8BX compatible with the 1790D‑8BV8B base?
Yes. The output common type matches the 1790D‑8BV8B base module. Always verify your base module’s model before installation.
| Brand Name | Allen-Bradley |
| Model No. | 1790-T8BV8BX |
| Product Type | Digital Expansion Module |
| hasMerchantReturnPolicy | Adjust according to reality |
| Shippingdetails | Adjust according to reality |
