They do say it was tested, and it worked ( for them) Just wondering if there is a trick?
see http://h71000.www7.hp.com/doc/84final/6048/6048pro_096.html
or here
The following devices have been tested on OpenVMS:
Inside Out Networks EDGEPORT/416 (DB9) and EDGEPORT/8 (DB25)
The EDGEPORT/416 DB9 (DIGI Part Number 301-1000-10) is a dual RS232 controller with 8 lines per controller (and a total of 16 lines). The device is packaged as two 8-line controllers behind a USB hub; it also provides 4 additional USB expansion ports. The device is powered from a DC adapter integrated on the back of the device.
The EDGEPORT/8 DB25 (DIGI Part Number 301-1016-08) is a single RS232 controller with a total of 8 lines. The device is bus powered and does not require an external power supply.
These devices are rack mountable. Both devices have a unique serial number; they are always assigned the same name, regardless of the USB port into which they are plugged. Testing of these devices shows reliable operation in both software flow control and raw binary (no flow control) modes at up to 115,200 baud.
The system parameter TTY_SILOTIME controls latency; it trades throughput and system overhead for latency. The default value for TTY_SILOTIME is 8. This value is multiplied by 100 and is used to represent the number of times a query is sent to the device for more data after a character transmit or receive.
If no input (or no subsequent output) is seen after 800 responses to the query, the driver stops sending queries to the device and waits for an input interrupt. Reducing the TTY_SILOTIME value allows the device to buffer more data, with slightly higher latency.
Increasing the value of TTY_SILOTIME makes the device more sensitive to latency but decreases buffering and overall throughput; it also adds more system and USB overhead. Setting TTY_SILOTIME to zero causes the driver to send input queries to the device continually. This setting causes the lowest latency, the highest system overhead, and the lowest throughput possible.
Note
The TTY_SILOTIME system parameter has no effect on Prolific or FTDI devices. The EDGEPORT controller design is different from devices that do not respond to a request until the device has data and a buffer timeout is reached. As a result, input data is buffered whenever possible.
In contrast, the EDGEPORT, responds immediately to input requests regardless of the amount of data available, and sends asynchronous reports about the availability of new data. This allows either a highly buffered implementation or one that is similar to polling.
Cool Gear (VScom) FTDI 8-Port RS232 (DB9)
This device (USBGEAR.COM Order Number 8XDB9-USB) is an 8-port DC adapter-powered device that contains 8 individual FDTI FT232BM chips and configures as 8 individual single-line controllers.
The controllers have unique serial numbers and are always assigned the same OpenVMS name, regardless of the USB port into which a controller is plugged.
Tests of this device show reliable operation in both software flow control and raw binary (no flow control) modes at up to 115,200 baud.
Prolific PL2303 4-Port RS232 Cable Dongle (DB9)
This device (USBGEAR.COM Order Number USBG-4X232) is a 4-port wire dongle (4 wires connected to a single USB connector), with 4xDB9 connectors on the wires. The cables contain a USB hub and 4 PL2303 serial controllers. The device is bus powered and does not need a separate power supply.
This device provides no serial number. The persistence of its name is based on where it is plugged (that is, its path topology); when the device is plugged at a different location, it appears to be a different instance of the device.
Tests of this device show reliable operation in both software flow control and raw binary (no flow control) modes at up to 115,200 baud.
FTDI 232AM Single-Port RS232 Dongle (DB9)
This device (USBGEAR.COM Order Number USBG-232MINI) is a single-port dongle (no wire) that plugs into a single USB port. The device is bus powered and needs no external power supply.
The device provides a serial number and is configured with the same OpenVMS device name regardless of where it is plugged.
Tests of the device show reliable operation in both software flow control and raw binary (no flow control) modes at up to 115,200 baud.
USBG-4-DOC-1 Multifunction Docking Station
This multifunction device (USBGEAR.COM Order Number USBG-4-DOC includes the following:
1 Prolific RS232 (DB9) serial port
A PS2-USB keyboard port converter
A PS2-USB mouse port converter
A bidirectional parallel port
A 4-port USB hub
This device is useful when only a single line is needed and when a parallel port, PS2 keyboard or mouse connectivity, or additional USB ports are required.
The device provides no serial number, and its name persistence is based on where it is plugged (path topology). When the device is plugged in at a different location, it appears to be a different instance of the device.
Tests of this device show reliable operation in both software flow control and in raw binary (no flow control) modes at up to 115,200 baud.