7. Technical Specification of VFX-250S
7.1 Network & User Interface
Connector:
Female 37-pin D type to user equipment (Video codec) Male 37-pin D type to network equipment (FRAD)
Interface:
RS449 (X.21, V.35 and others with adapter cables) RS422 balanced drivers and receivers and RS423 receivers
7.2 User Interface
Clock Rates:
VFX-250S can accept external TT clock or it can supply clock to user equipment at the following speeds: 64, 96, 128, 192, 256, 384, 512, and 768 Kbps, plus 1.024, 1.536, and 1.920 Mbps
Transmission:
Supports continuous full duplex data transfer at specified clock rates.
7.3 Network Interface
Clock Rates:
VFX-250S requires clock from network (up to a maximum of 2.048Mbps).
Packet Parameters:
Packet Length: 10 - 4095 bytes
DLCI: 2 byte
FCS: standard 2 bytes
7.4 Enhanced Buffer Management
A unique underlying protocol is used to negotiate a Master/Slave relationship between two communicating VFX-250S units. This allows for an "end-to-end" management of the buffers to provide a "slip-free" data transfer. An Automatic Variable Buffer (AVB) feature is provided in order to smooth the potential differences in delays across the range of user port clock speeds.
7.5 Serial Management Interface
Connector:
Female 9 pin D type
Interface:
EIA-232, 9.6 Kbps & 19.2 Kbps, 8 bits/no parity/1 stop bit
Configuration:
Windows-based configuration software is provided with the VFX-250S which allows for the management of all the options within the unit. Alternatively, a "dumb" terminal can be used to access the menu driven configuration system directly. Available Settings:
∙User defined Site Name
