Features / Benefits
- Interface - X.21, ITU V.11, (5) DB-15 Female Connectors
- Data Rates - Synchronous up to 1.024Mbps
- Anti-Streaming - Automatic or Manual for unattended Circuit Restoral
- Individual Subchannel Enable/ Disable Switches
- Integral Elastic Tail Circuit Buffer - FIFO capable of 512 bits per channel
- Up to Four DTE or DCE's per Link
- Transparent to Data
- Supports Fall Back Clocking
- Sturdy Metal Enclosure
- 110/220VAC Switch Selectable
Description
The X.21 Digital Sharing Device DMM-X21 provides the network manager with a cost effective means of expanding existing, leased line polled networks without adding computer ports or communications links. With the DMM-X21, up to 4 DTE or DCE devices can share the same port and communications link using the contention and control protocols normally resident in the host hardware and software.
Once installed, system and network efficiency are increased through higher host processor utilization coupled with the significant decrease in idle time between host / terminal traffic sessions.
Ideal for synchronous network environments, the DMM-X21 is protocol transparent at data rates up to 1.024Mbps. Data arriving at the Master Port is continually broadcast to all Subchannels. The attached terminal device that raises the Control (C) or Indicate (I) signal is automatically given control of the DMM-X21 until data transmission is complete. Clocking is accomplished from the attached Digital Modem.
The DMM-X21 incorporates optional Anti-Streaming circuitry. If enabled, Anti-Streaming will automatically remove a defective terminal from service if the Control (C) or Indicate (I) signal is present longer than the user predefined selection period.
Elastic Tail Circuit Buffers compensate for systems having different clock sources. Large 512 bit buffers enable the DMM-X21 as an ideal choice for VSAT or land line applications.
The DMM-X21 is equipped with an internal 110/220VAC switch selectable linear power supply and has a three year warranty.
SPECIFICATIONS |
|
| Application | Multiple X.21 Synchronous DCE or DTE devices contending in a polled environment, to share one Digital DCE or DTE interface |
| Capacity | One to Four CCITT X.21 devices |
| Interface | CCITT X.21, V.11 using DB-15 female connectors |
| Data Format | Data transparent at all data rates |
| Data Rates | Up to 1.024Mbps |
| Timing | From Composite (Master) Port,Sub-channel Port 1 or Port 4 |
| Buffers | Up to 512 bits per channel |
| Anti-Streaming | Automatic.....Selectable time out intervals
Disable.........Selectable via dip switch |
| Front Panel | Indicators....Power, Send/Receive Data, Channel Active, Channel Stream
Switches.....Enable/Disable of each Subchannel |
| Power Source | 100-120 to 200-220VAC @10%, 50/60Hz, 0.32/0.16A, external 110/220 volt select switch, IEC Power Inlet, (2) 5mm Fuses |
| Environmental | Operating Temperature . .32º to 122º F (0º to 50º C)
Relative Humidity.. . . . . . .5 to 95% Non-Condensing Altitude. . . . . . . . . . . . . ... .0 to 10,000 feet |
| Dimensions | Height ....... 1.75 inches (4.44 cm)
Width ........ 17.00 inches (43.18 cm) Length ....... 9.00 inches (22.86 cm) |
| Weight | 4.5 pounds (2.1Kg) |
| Warranty | Three Years, Return To Factory |
| Regulatory Approvals Tested According to | UL 60950-1:2003, CAN/CSA-C22.2 No. 60950-1:2003CE Safety EN60950 and CE EMC EN300-386-2 |
| Ordering Information | Model: DMM-X21 Description: 4 Port Digital Sharing Device |
| Included with each unit: | 1) Operations Manual
2) U.S.A. Grounded Power Cord, Part # 713015 3) Optional Power Cords ....A) United Kingdom, Part # 713016 ....B) Continental Europe, Part # 713017 ....C) Other: Specify Country on Purchase Order 1) Spare Data Center Fuses ....A) 160ma Fuse, Qty (2) Part # 714000 ....B) 80ma Fuse, Qty (2) Part # 714001 |