Nec Corporation

Nec Communications Systems, Ltd.

Nec Communication System

Yoshiaki Numata

Minoru Shinta

In a LAN relaying apparatus, a reception side control circuit receives a reception side write pointer from a reception side write control circuit and a reception side read pointer from a reception side read control circuit, and determines a reception side pointer difference between the side reception side write pointer and the reception side read pointer. Then, the control circuit controls the reception side read control circuit to start the second side read operation when the reception side pointer difference is equal to a reception side first threshold held therein. Subsequently, the reception side control circuit controls the reception side write control circuit and the reception side read control circuit such that the first side write operation or the second side read operation is carried out based on the reception side pointer difference, when the reception side pointer difference is not equal to the reception side first threshold after the start of the second side read operation.

Adaptive access control in LAN relaying apparatus

Disclosed is a FAX signal transmission system, in which the transmission side and the reception side are inter-coupled by a bearer. Each side is constituted by DCME comprising a transmission side, which includes a signal identification circuita FAX data allotment control circuita delay circuita FAX data demodulation circuita FAX data allotment signal generation circuitand a multiplexing circuitand a reception side, which includes a FAX data distribution control circuit, a FAX data transmission circuit and a FAX data remodulation circuit. The transmission side is provided with a control terminal for inputting signal identification data. The input signal identification content of the signal identification circuitcan be changed according to the signal identification data.

Facsimile signal transmission system

A facsimile module self-diagnostic system is provided that can detect a failure occurring in the transmission-side demodulation circuit or in the reception-side re-modulation circuit in a facsimile module. A test facsimle signal generation circuit ( ) is provided on the transmission side of the facsimile module. A test facsimile signal judgement circuit ( ) is provided on the reception side of the facsimile module. In a test facsimile signal judgement zone, the test facsimile signal judgement circuit ( ) inspects a test DCS (Digital Command Signal) signal at the first stage and inspects a test TCF (Training Check) signal at the second stage.

Facsimile module self-diagnostic system for digital circuit multiplication equipment

A facsimile transmission apparatus includes a demodulator, an identifier, a control signal generator, a variable delay controller, and a multiplex transmission unit. The modulator demodulates a facsimile signal to output a demodulated signal. The identifier identifies the facsimile signal as one of a predetermined low-speed signal and a predetermined high-speed signal to output an identification signal. The control signal generator generates facsimile control channel (FCC) messages for controlling a protocol between facsimile apparatuses on the basis of the identification signal from the identifier. The variable delay controller performs variable delay control for the FCC messages from the control signal generator such that the FCC messages can be transmitted in a generation order. The multiplex transmission unit multiplexes each variably delayed FCC message from the variable delay controller with a demodulated signal, from the demodulator, corresponding to the variably delayed FCC message to transmit a multiplexed signal.

Growing community of inventors

Miyagi, Japan

Yoshiaki Numata