Electrical Specifications; Software Specifications - Toa NX-100 Cookbook

TECHNICAL NOTE
NX-100 Serial Communication

Electrical Specifications

• The D-sub 9-pin connector used for the NX-100's serial bridge comprises a DCE circuit. Of its
9 pins, only the GND (pin 5), TxD (pin 3), RxD (pin 2), RTS (pin 7) and CTS (pin 8) pins are wired.
Since other pins are not wired, they cannot be used for connection, flow control or verification.
• Regarding output pins, until data communications are started after activation, the RxD pin
(pin 2) is kept at low voltage level, while the CTS pin (pin 8) is kept at high voltage level.
As long as the NX-100 Setting's Flow Control is not set to "Hardware," the CTS pin is kept at
high voltage level even during communications.
• Setting the NX-100 Setting's Flow Control to "Hardware" executes the "RTS-CTS handshake"
which informs serial-connected equipment of the receiving status of connected equipment
data (transmitting status to the network) through the CTS pin, or controls data transmission to
serial-connected equipment by checking the RTS pin status.
• If the Flow Control is set to "Software," the CTS pin's output does not change. However,
"XON/XOFF system" flow control functions when the request to resume transmission
(11H, CTRL-Q) and the request to stop transmission (13H, CTRL-S) are simultaneously
transmitted to each other.

Software Specifications

TCP session connection processing flow
When a TCP error and an alive check (30-second interval) error occur during communications
between the connected TCP server and the set NX-100, the NX-100 designated as the TCP client
cuts off the TCP session and begins to retry the session connection after a 5-second interval.
The TCP client continuously retries failed session connections to the server. The in-session TCP
server connected to the designated NX-100 TCP client cuts off the TCP session and waits for
connection if a TCP error and an alive check (30-second interval) error occur during
communications with the designated NX-100 TCP client.
Serial Reception-to-Packet Transmission Processing Flow
UDP/TCP Transmission
• Previously received serial data is transmitted as packets at 20 millisecond intervals. There
are cases in which even consecutively received serial data is transmitted in two packets at
20 millisecond intervals. Also, unless an interval of 20 millisecond or more exists between
two serial data transmissions, they may be transmitted as the same packet with essentially no
interval between the two.
Packet Reception-to-Serial Transmission Processing Flow
Both the UDP and TCP transmissions begin to output serial data as soon as a packet is received.
Specifications
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SERIAL COMMUNICATION