General
Number of ports	8 -

The Moxa OPT8A+ is an RS-232 connection box serving as an interface extension for serial devices. It enables the connection of up to eight RS-232 devices to a serial expansion card in the host system. The box is specifically designed for industrial applications requiring stable and reliable serial communication. Device-side connections are made via DB25 connectors (female), while the board-side connection is implemented using a VHDCI 68 connector. This connection is designed for direct attachment to corresponding expansion cards in computers or industrial PCs. The connection is made via a 1.5 m cable, which, depending on the model, connects VHDCI 68 to DB62 or VHDCI 68 to DB62.

Applications

The OPT8A+ is suitable for industrial environments where multiple serial devices such as sensors, measuring instruments, printers, or control units need to be connected to a central system. Typical use cases include production plants, automation systems, or building automation. The box is designed for environments with high requirements for signal integrity and electromagnetic compatibility. However, the OPT8A+ does not feature specific ESD or EFT protection functions—these are only available in the OPT 8S models.

Functions and Equipment in Detail

Each of the eight serial ports features LED indicators for transmit (TxD) and receive activity (RxD). These provide visual monitoring of communication and facilitate troubleshooting. The LEDs indicate whether data is being transmitted, which is useful during commissioning or when faults occur. The supported baud rate ranges from 50 bps to 921.6 kbps, ensuring broad compatibility with various serial devices. The maximum data rate is sufficient for most industrial applications and enables fast communication.

Technology Explained Simply

The OPT8A+ functions as a passive extension of the serial interface. It transmits signals between the host system and connected devices without any internal signal processing. The connection is made via a fixed cable directly attached to the expansion card. The DB25 connectors on the device side are standard for RS-232 communication. The use of VHDCI 68 on the board side is typical for industrial interface cards, often installed in rack systems or specialized computers. The box itself does not have its own power supply, as it is powered through the host system.

Compatibility and Accessories

The OPT8A+ is compatible with serial expansion cards featuring a VHDCI 68 connector. The connection is made via the included 1.5 m cable. Devices connected to the DB25 connectors must also be RS-232 compatible. The box is part of a product family that also includes models with DB9 or RJ45 connectors; however, the OPT8A+ is specifically designed for DB25 connectors.

Mounting and Installation

Installation involves directly connecting the VHDCI 68 connector to the serial expansion card in the host system. The cable is connected to the box, and the DB25 connectors are attached to the respective RS-232 devices. Mounting requires no special tools, as it uses plug-in connectors. The box is compact and can be placed close to the devices to minimize cable losses and signal interference. Dimensions are 247 × 108 × 35 mm, allowing placement in standard rack systems or on workstations.

Advantages in Operation

The OPT8A+ provides a simple and reliable way to connect multiple serial devices to a host system. The integrated LEDs simplify diagnosis of communication issues. Support for a wide range of baud rates ensures flexibility when integrating various devices. The use of standardized connectors (DB25, VHDCI 68) ensures high compatibility with existing systems. The box is designed for industrial environments, with mechanical stability and robust construction supporting reliability in continuous operation.