The value of Termination Character is appended to the end of all writes.Ī serial break is sent after each write. The write sends all but the last character with the highest bit clear and transmits the last character with the highest bit set. No termination character is appended to writes. We will discuss each property in detail and then discuss special considerations. The message-based properties are Termination Character and Termination Character Enabled, and the serial-specific properties are Serial End Modes for Reads and Serial End Modes for Writes. Two fall under Message-Based Settings, and the other two under Serial Settings. Two common termination characters are Line Feed (codes display '\n', ASCII decimal 10, or hex 0x0A) and Carriage Return (codes display '\r', ASCII decimal 13, or hex 0x0D).įour main NI-VISA properties deal with termination. You need to tell VISA how messages are terminated only when using other VISA resource types (Serial Instr, USB Raw, and TCPIP Socket).īoth incoming and outgoing messages can have termination characters. For VISA resource types that correspond to a complete 488.2 protocol (GPIB Instr, VXI/GPIB-VXI Instr, USB Instr, and TCPIP Instr), you generally do not need to use termination characters, because the protocol implementation also has a native mechanism to specify the end of a message. Various message-based buses use termination characters to indicate the end of a message transmission.
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