Sealevel SeaLINK Ethernet serial servers support a 2-byte format to marshal 9-bit serial data between the host computer and the serial server. The least signif
… View More
Resource Center
Browse Categories
How do SeaLINK Ethernet serial servers transmit modem control signals in serial tunneling mode?
Jul 30th 2011
SeaLINK Ethernet serial servers use RFC-2217, the Telnet COM port control protocol, to transmit modem control signals in serial tunneling mode. Since S
… View More
How do you transmit a continuous stream of synchronous serial data without any “idle time”?
May 27th 2011
Sealevel synchronous serial adapters are capable of a constant output stream if the application program can provide a constant stream of serial data. If you ar
… View More
Sealevel synchronous serial adapters support the three most common non-encoded clocking modes:The Sealevel serial adapter provides the clock using the baud ra
… View More
What is the extra data transmitted between Sealevel Ethernet Serial Servers and the SeaLINK driver?
Apr 29th 2011
The extra data is non-serial Telnet command messages such as COM port settings and modem control signals. SeaLINK devices communicate using the RFC-2217
… View More
Manchester clock encoding (also known as split phase or bi-phase level encoding) always produces a transition at the center of the bit cell.Sealevel synchron
… View More
To optimize a SeaLINK Ethernet serial server for lower latency, disable Nagle’s algorithm on both the SeaLINK device and virtual COM port driver.
… View More
By default, SeaLINK Ethernet serial servers use Nagle’s algorithm to reduce network traffic and increase serial data throughput, with the side effect o
… View More
Sealevel USB serial adapters are supported by the SeaCOM driver, which includes a latency timer with a default setting of 16 msec. Decreasing this value redu
… View More
OverviewThis condition is potentially encountered in Microsoft Windows when connecting a serial GPS device to a serial port. It is caused when the NMEA 0183 GPS
… View More
Why does the mouse cursor randomly jump around when I connect a GPS to a Sealevel serial adapter?
Feb 2nd 2011
You are describing the “crazy mouse” syndrome, a common condition when Microsoft Windows receives NMEA 0183 data from a serial GPS device. The conditio
… View More
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 aid in transfer efficiency, the Wi
… View More
The Z16C32 operates similar to a UART and transmits the least significant bit first. The only exception is when the card is operating in SDLC/HDLC mode wit
… View More
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 utility allows the B
… View More
What CRC-CCITT value is used by Sealevel synchronous serial adapters with the Zilog Z85230?
Dec 29th 2010
The CRC-CCITT polynomial value used in the Zilog Z85230 is:x16 + x12 + x11 + x10 + x8 + x3 + x2 + x1 + 1The corresponding hexadecimal value is 0x1D0F.
… View More
What CRC-CCITT value is used by Sealevel synchronous serial adapters with the Zilog Z16C32?
Dec 29th 2010
The CRC-CCITT polynomial value used in the Zilog Z16C32 is:x16 + x12 + x5 + 1The corresponding hexadecimal value is 0x1021.
… View More
What is a CRC in synchronous serial communications?
Dec 29th 2010
The Cyclic Redundancy Check (CRC) is a check value used to detect transmission errors in a frame or block of data. The transmitter encodes the calculated CRC
… View More
Section 2.5 of the ITU O.151 document basically states that a pattern can be encapsulated by the framing bits of a protocol, if necessary. Therefore, the BE
… View More