Mte-2

Transcript

ORDERING MTE-2 MTE-2 Miniature Tail-End Adapter Miniature Tail-End Adapter Specifications are subject to change without prior notice. 234-100-12/98  1998 RAD Data Communications Ltd. FEATURES • • • • • • DCE to DCE connection DESCRIPTION • Two internal 64-bit buffers Data rates up to 256 kbps Easy to install No AC power required Compact, lightweight • MTE-2 is a miniature tail-end adapter, enabling the connection of two independently clocked DCEs. When two internally clocked devices exchanging data cannot be clocked externally, MTE-2 is used as an interface between them. MTE-2 employs two 64-bit buffers to reduce errors caused by drift between the two DCE clocks. Initial setting of the buffers is dependent upon the position of the two DCD straps, DCD-1 and DCD-2, which control buffers A and B, respectively (see Figure 1). Operation with the DCD straps ON will normally prevent block errors. • A schematic diagram (Figure 1) shows the flow of data clocking in and out of the buffers, as follows: − − Receive Clock (pin 17) of modem A clocks Receive Data (pin 3) into buffer A. Transmit Clock (pin 15) of modem B clocks Transmit Data (pin 2) out of buffer A. Receive Clock (pin 17) of modem B clocks Receive Data (pin 3) into buffer B. Transmit Clock (pin 15) of modem A clocks Transmit Data (pin 2) out of buffer B. The buffer setting is as follows: − APPLICATION − DCD strap OFF: The buffer has adaptive centering which automatically adjusts to “almost full” (in case of underflow) or “almost empty” (in case of overflow). DCD strap ON: The buffer setting occurs when the DCD signal goes off. It is set at 32 bits (in the middle). Each time the signal drops after it has been active, it should remain off for at least 64 clock intervals in order to reposition the buffer at 32 bits. When the DCD signal is on, the data is transferred transparently through the buffer. The DCD signal should stay active for at least 32 bits. Figure 1. Schematic Diagram of Data Flow through MTE-2 SPECIFICATIONS • Transmission Format Synchronous, transparent to protocol • Transmission Mode Half or full duplex, with or without Carrier Detect signalling (DCD) • Data Rate Up to 256 kbps • Modem-to-Modem Buffering Buffer A and buffer B, full-duplex DCD=ON: 64-bit buffer, set to 32 bits while DCD signal (pin 8) is inactive; DCD=OFF: 64-bit buffer, set to 8 bits in case of overflow or set to 56 bits in case of underflow • Connectors Two 25-pins, D-type, female • DCE to DCE Connection • Physical Length: 135 mm / 5.3 in Height: 30 mm / 1.2 in Width: 53 mm / 2.1 in Weight: 150g / 5.3 oz • Environment Temperature: 0-50°C / 32-122°F Humidity: up to 90%, non-condensing Declaration of Conformity RAD Data Communications Ltd. Mfr. Name: Mfr. Address: 12 Hanechoshet St. Tel Aviv 69710 Israel declares that the products: Product Name: MTE-2 Conform to the following standard(s) or other normative document(s): EN 55022 (1994): Limits and EMC: methods of measurement of radio disturbance characteristics of information technology equipment. EN 50082-1 (1992): Electromagnetic compatibility Generic immunity standards for residential, commercial and light industry. Supplementary Information: The product herewith complies with the requirements of the EMC Directive 89/336/EEC. The product was tested in a typical configuration. MTE-2 provides cross cable function • Power No AC power required, uses ultra-low power derived from the RS-232/V.24 data and clock signals Tel Aviv, March 31st, 1996 Haim Karshen Quality Manager European Contact: RAD Data Communications GmbH, Lyoner Strasse 14, 60528 Frankfurt am Main, Germany Table 1. Strap Selection INSTALLATION Caution. This is a delicate instrument. Be careful when setting jumpers or performing any actions within the product so that you do not break or shake any components. MTE-2 is factory strapped for adaptive centering (DCD=OFF) and may be plugged directly to DCEs. If DCD centering is required, change the strapping as follows: 1. 2. 3. Open the unit by pressing the cover at the marked places on the sides. Gently remove the upper part by lifting it up with your fingers. To select DCD control for each side, J1 and J2, set the DCD1 and DCD2 jumpers in accordance with Table 1 and Figure 2. Figure 2. Strapping Diagram Strap Identity Possible Settings DCD1 OFF ON DCD2 OFF ON Function Buffer A operation has adaptive centering J1 Buffer A is controled by pin 8 of J1 Buffer B operation has adaptive centering J2 Buffer B is controlled by pin 8 of J2 Factor y Setting OFF OFF 4. Restore the upper part by pressing it gently to the main board. 5. Close the unit and connect it directly to the two DCEs.