A “stack” or “chain” of SeaI/O modules, connected via the pass-through connectors or screw terminals on the left side of the enclosure, communicates via an…
How Do I Perform a Loopback Test on my PCIe Async Card?
In the video below, a member of the Sealevel support team walks through the process of setting up a loopback test for a PCIe Asynchronous…
How do you patch the 8250_exar driver in RHEL 8 and 9 for Sealevel XR17V35X cards?
This is intended for RHEL 8 and RHEL 9 users impacted by the communication issues described in this support article regarding Sealevel’s XR17V35X-based serial devices (7xxxec serial…
What is EtherNet/IP?
EtherNet/IP is open-source and is managed and developed by the Open DeviceNet Vendors Association (ODVA), a tax-exempt business league that includes a wide variety of…
What is Modbus?
Modbus, initially developed in 1979, is one of the oldest, most widely used industrial communications protocols. Traditionally, Modbus was/is implemented using RS-232, RS-422, or RS-485…
SeaMAC: ssiEncodingNone vs ssiEncodingNrz
Is the 7203e PCIe serial interface dip switch or software configurable to change the RS-485 termination from a 120 Ohm resistor to an AC termination?
Sealevel’s 7203e does have onboard dip switches that would allow you to turn off the 102 Ohm resistor; the 120 Ohm resistor can be changed through dip…
Parity, Checksum, and Cyclic Redundancy Check (CRC)
Parity is actually an extra bit that’s added to every data word. It can detect a one bit error within that data or byte Checksum…
Raw Mode or Bit-Shift Mode
Raw mode is actually the simplest form of communication. The card takes every bit of data that’s received from the communication line, groups it into…