Rabbit EM1500, Product Manual, Page: 106 / 120

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Glossary of Terms
DCD
Data Carrier Detect indicates that a good carrier is being received from the remote modem.
This is asserted by a DCE (e.g. a modem) when it detects the data carrier signal on the telephone line.
DNS
Domain Name Service is the distributed database of alphanumeric name and IP address pairs.
DSR
Data Set Ready, a handshaking signal driven by a DCE device to tell the DTE device that it is ready.
This signal is sometimes used for flow control, but is more usually a unit readiness indicator.
DTE
Data terminal equipment is a term that describes the pins of a serial connector and their signal direc-
tion.
• Tx - output to send data
• Rx - input to receive data
• RTS - Ready to Send, an output asserted when the DTE is ready to receive
• CTS - Clear to Send, an input the DTE waits for before sending
• DTR - Data Terminal Ready, an output to indicate readiness
• DSR - Data Set Ready, an input to indicate readiness of the attached device
• DCD - Data Carrier Detect (aka., RLSD, Receive Line Signal Detect), an input the DTE
expects will be asserted before receiving
The EM1500 may be used as either a DTE device or a DCE device, depending on the serial port being
used. SER1 is a DTE device. SER3 may also function as DTE device.
DTR
Data Terminal Ready, a handshaking signal driven by a DTE device to tell the DCE device that it is
ready. This signal is sometimes used for flow control, but is more usually a unit readiness indicator.
EMC
ElectroMagnetic Compatibility, describes compliance with a set of regulations that control the emmis-
sions of and susceptibility to EMI.
EMI
ElectroMagnetic Interference, an electrical disturbance in a system.