This document describes a USB to RS-232 adapter, available in several models: USC-232F, USC-232G, USC-232TB, USC-102F, USC-104F, and USE-070.
Function Description:
The USB to RS-232 adapter serves as a bridge between Universal Serial Bus (USB) ports and RS-232 enabled devices. USB technology has become prevalent due to the increasing number of external peripheral devices (scanners, digital cameras, portable hard-disk drives, cell phones, PDAs, MP3 players, etc.) connecting to modern PCs. USB functions similarly to conventional bus ports like Serial (COM), Parallel, and PS/2, but with the advantage of not requiring IRQs, allowing more devices to be connected without conflicts. This converter provides an external plug-and-play connection, enabling RS-232 devices to communicate with PCs or any computing devices that support the USB specification. The converter is equipped with standard connectors for Serial DB-25 or DB-9, and USB Type A or B, to meet various working requirements. By linking a USB to Serial cable, seamless communication is established. For user convenience, the device draws power directly from the Universal Serial Bus, eliminating the need for an external power supply. As a USB-compliant device, it supports features such as plug-and-play, hot-swapping, and energy-saving suspend and resume modes. Given that most computers have limited USB and COM ports, USB hubs can be utilized to expand the number of USB ports for connecting multiple USB peripheral devices.
Important Technical Specifications:
- Models: USC-232F, USC-232G, USC-232TB, USC-102F, USC-104F, USE-070
- Chipset: FTDI
- USB Compliant Version: USB 1.1 & 2.0
- Data Speed (USB): 1.5 / 1.2 Mbps
- Data Speed (Serial): 230K bps
- Connectors:
- Host: USB A/M (for USC-232F, USC-232G, USE-070) or USB B/F (for USC-102F, USC-104F)
- Device: DB-9/M (for USC-232F, USC-232G, USE-070), DB-9/M2 (for USC-102F), DB-9/M4 (for USC-104F)
- Power Mode: Bus-powered (draws power from USB)
- Cable Length:
- USC-232F: 1M
- USC-232G: 1.8M
- USC-102F: 0.6M
- USC-104F: 1.8M
- USE-070: 70M
- Housing Material:
- USC-232F: PVC
- USC-232G: Plastic
- USC-102F: Plastic
- USC-104F: Aluminum
- USE-070: Plastic
- Pin Assignments (DB-9):
- 1: DCD (Data Carrier Detected)
- 2: RxD (Receive Data)
- 3: TxD (Transmit Data)
- 4: DTR (Data Terminal Ready)
- 5: GND (Signal Ground)
- 6: DSR (Data Set Ready)
- 7: RTS (Request To Send)
- 8: CTS (Clear To Send)
- 9: RI (Ring Indicator)
- Pin Assignments (DB-25):
- 2: TxD (Transmit Data)
- 3: RxD (Receive Data)
- 4: RTS (Request To Send)
- 5: CTS (Clear To Send)
- 6: DSR (Data Set Ready)
- 7: GND (Signal Ground)
- 8: DCD (Data Carrier Detected)
- 20: DTR (Data Terminal Ready)
- 22: RI (Ring Indicator)
- Pin Assignments (Terminal Block - USC-232TB):
- 1: Tx (Transmit Data)
- 2: RTS (Request To Send)
- 3: Rx (Receive Data)
- 4: CTS (Clear To Send)
- 5: G (Signal Ground)
- System Requirements:
- Windows: 98 / ME / 2000 / XP / Vista / 7 / 8 / 2003 / 2008 / 2008R2
- WinCE: V4.2 ~ V7.0
- Mac OS: 8.x / 9.x / 10.x
- Linux: Kernel 1.5.0 or above
- System must be equipped with USB Host Controller
Usage Features:
- RS-232 Communication via USB: Enables RS-232 interfaced devices to communicate with a PC through a USB port.
- Independent Port Configuration: Each port can be independently configured for various synchronous and asynchronous interfaces.
- Device Configuration: Supports default ROM or external EEPROM for device configuration.
- Plug & Play and Hot-Swapping: Allows for easy installation and removal without system restarts.
- High Transfer Rate: Achieves over 1Mbps transfer rate per port.
Maintenance Features:
- Driver Installation: Detailed instructions are provided for Windows 98, Windows 2000, Windows CE, Windows XP, Windows VISTA (Win 7 & Win 8), and MAC OS. Users are guided through the process of locating and installing the correct drivers.
- Driver Uninstallation: Comprehensive instructions are included for uninstalling drivers on Windows 98, Windows 2000, Windows XP, Windows VISTA, and MAC OS. This typically involves using the Add/Remove Programs utility or the Device Manager to ensure a clean removal of files and registry entries. For Windows XP, manual removal of OEM INF and PNF files may be necessary.
- Troubleshooting: The manual addresses common issues such as:
- Windows failing to find device drivers (often due to VID/PID mismatch in EEPROM or INF files).
- Windows forcing a reboot after installation (usually due to file access conflicts during driver copying).
- Driver installation failures with Windows error code 10 (indicating hardware issues, insufficient power, or incorrect USB root hub drivers).
- Device hanging randomly under Windows 98 (suggests hardware compatibility issues, possibly resolved by adding capacitors to USBDP/USBDM lines).
- Windows 98 complaining about missing .CAT files (signature files for WHQL certified drivers; can be skipped if not certified).
- Windows 98 complaining about missing
ftccomms.vxd file (requires browsing to driver file location during installation).
- "Unidentified USB Device" dialog not displayed or "Error installing USB driver" messages in Windows CE (check driver file names, VID/PID matching, and registry settings).
- Bytes missing or data corrupt in Windows CE (can be due to host driver failing to send vendor commands, resulting in incorrect Baud rate).
- Driver not sending or receiving data in Windows CE (test with VCPTest, check Baud rate).
- Device not appearing in
/dev directory or "New Port Detected" not displayed in System Preferences-Network on MAC OS (may indicate unsupported device ID, requiring EEPROM disable or contacting FTDI support).
- Device not accessible despite supported ID on MAC OS (check driver ownership and permissions, use
chgrp command).
- Windows Vista (Win 7, Win 8) warning about uncertified drivers (allows "Install this driver software anyway" option).
- Driver not installing on VISTA x64 (requires certified drivers; contact vendor if customized driver is not re-certified).
- Regulatory Compliance:
- FCC: Complies with FCC Rules; operation subject to two conditions: no harmful interference, and acceptance of any interference received.
- CE: Complies with EN 55022: CLASS B regulations.
- RoHS: All package contents (products, packing materials, documentation) comply with RoHS.
- Driver Updates: Users are advised to download the latest drivers from the FTDI website (
www.ftdichip.com/Drivers/VCP.htm) if they encounter difficulties with the provided drivers.
- Multi-Port Converters: For multi-port converters (e.g., 2-port or 4-port), each port requires individual driver installation.
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