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The Black Box SP390A-R3 is a professional USB-to-RS422/485 media converter designed to provide reliable serial communication between USB-equipped systems and RS-422/RS-485 devices. Featuring built-in opto-isolation, it ensures safe data transmission by protecting connected equipment against surges, ground loops, and electrical noise.
As part of the Black Box connectivity portfolio, the SP390A-R3 combines durability and advanced protection in a compact form factor. It’s ideal for industrial, commercial, and lab environments requiring stable and secure communication between modern USB hosts and legacy serial equipment.
The SP390A-R3 converts USB input to RS422/RS485 outputs seamlessly, supporting both half- and full-duplex communication. Its opto-isolation design ensures galvanic isolation between the USB interface and serial line — improving safety and data integrity in electrically noisy environments.
This Converteris powered through the USB port, requiring no external adapters. Automatic sensing for RS‑422/485 communication and easily installed drivers provide plug‑and‑play functionality. Rugged enclosure and stable construction meet the needs of factory automation, SCADA, point-of-sale, and test bench environments.
The Black Box SP390A-R3 delivers high reliability and secure data transmission even in demanding industrial conditions. Its optically isolated design ensures devices remain protected from damaging electrical conditions, while maintaining consistent throughput for mission-critical data communication.
| Specification | Details |
|---|---|
| Part Number | SP390A-R3 |
| Brand | Black Box |
| Product Type | USB to RS‑422/485 Media Converter |
| Interface 1 | USB 2.0 Type A Male |
| Interface 2 | RS‑422/RS‑485 (DB9 or terminal block) |
| Supported Modes | RS‑422 full duplex / RS‑485 half & full duplex |
| Data Rate | Up to 921.6 kbps |
| Isolation | 2 kV Opto‑isolation |
| Indicators | LEDs for TX/RX activity, power |
| Power Source | USB bus‑powered |
| Enclosure | Rugged metal housing |
| Cable Length | 1.5 m integrated USB cable |
| Operating Temperature | 0°C to 50°C |
| Storage Temperature | -20°C to 70°C |
| Humidity | 5% – 95% non‑condensing |
| Compliance | USB 2.0, EIA/TIA RS‑422/485 |
| Certifications | CE, FCC, RoHS |
| Warranty | 2‑Year Limited Warranty |
| Environment | Industrial automation, SCADA, POS, IT labs |
| Country of Origin | Made by Black Box |

All packages are shipped same day if the order is placed before 3PM CST
We use UPS/FedEx to ship the packages with different service levels offered by UPS/FedEx
Overnight Shipping take 1 business day
Expedited Shipping take about 2-3 business days
Ground shipping take about 3-5 business days
You can select the desired service level at Checkout and we will make sure the package is shipped as per the selected service level.
We Accept
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ii) All Credit & Debit Cards
iii) Purchase Orders
iv) Check
v) Bank Transfer/ACH/Wire Transfer
To process the order through Paypal/CC, you can simply checkout and process the payment.
If you want to issue us Purchase Order/Check/Bank Transfer, Please contact us at the following details
Call: 469.458.9636
Email: sales@dcsupplies.net
If you have any queries, please contact us at the following details and we will be happy to help
Call
469.458.9636
469.458.9638
Email
sales@dcsupplies.net