Sealevel USB serial adapters are supported by the SeaCOM driver, which includes a latency timer with a default setting of 16 msec. Decreasing this…
How to fix “crazy mouse” syndrome with USB serial adapters
Overview This condition is potentially encountered in Microsoft Windows when connecting a serial GPS device to a serial port. It is caused when the NMEA…
Why does the mouse cursor randomly jump around when I connect a GPS to a Sealevel serial adapter?
You are describing the “crazy mouse” syndrome, a common condition when Microsoft Windows receives NMEA 0183 data from a serial GPS device. The condition occurs…
How is the memory accessed on the 3514 and the 5104 synchronous serial adapters?
The Zilog 16C32-based 3514 and 5104 have 256 K of memory on the adapters that are used for buffering the input and output data. To…
What bit order does the Zilog 16C32 chipset use for transmitting serial data?
The Z16C32 operates similar to a UART and transmits the least significant bit first. The only exception is when the card is operating in…
Can the BERT pattern be used at data rates above 14.4 Kbps?
The ITU document O.153 paragraph 2.1 indicates the BERT pattern can be used at data rates up to 14.4 Kbps. However, the Sealevel WinSSD…
What CRC-CCITT value is used by Sealevel synchronous serial adapters with the Zilog Z85230?
The CRC-CCITT polynomial value used in the Zilog Z85230 is: x16 + x12 + x11 + x10 + x8 + x3 + x2 +…
What CRC-CCITT value is used by Sealevel synchronous serial adapters with the Zilog Z16C32?
The CRC-CCITT polynomial value used in the Zilog Z16C32 is: x16 + x12 + x5 + 1 The corresponding hexadecimal value is 0x1021.
What is a CRC in synchronous serial communications?
The Cyclic Redundancy Check (CRC) is a check value used to detect transmission errors in a frame or block of data. The transmitter encodes…