The Digital Mixing Module DMM-4 is a digital sharing device or network expansion device for modem sharing or port sharing applications in polled, contention, SCADA and broadcast environments. The DMM-4 allows up to four RS-232 DCE or DTE devices to share a Modem /DSU or computer port. Each port is DCE /DTE selectable and has an 8 bit tail circuit buffer. Data rates of up to 128 Kbps are supported.
The RS-232 Port Sharing Device (DMM-4) is a network expansion device for modem sharing or port sharing applications in polled or contention environments. The DMM-4 allows up to four devices to share a modem /DSU or computer port. Any combination of terminals and modems may be used in a network environment.
Each port of the DMM-4 may be selected as a DCE or DTE interface.
Once installed, system and network efficiency are increased through higher host processor utilisation coupled with the significant decrease in idle time between host / terminal traffic sessions.
Ideal for either synchronous or asynchronous network environments, the DMM-4 is protocol transparent at data rates up to 128Kbps. The DMM-4 may be configured to provide clocking for the entire network. To prevent data transmission errors caused by clock differentials throughout the network, an 8 bit buffer is provided. In applications where the master port and the selected port provide their own clocks, data is clocked into the buffer at the receive clock rate of the active port and clocked out using the master port transmit clock.
In applications where the Clear To Send control signal is not provided by the master port, an artificial RTS /CTS is available. Additionally, several RTS /CTS delay settings are available.
The DMM-4 provides optional Anti-Streaming circuitry. Once enabled, Anti-Streaming will automatically remove a defective terminal or modem from service if the Data / Control criteria is present for the user predefined selection period.
Housed in a sturdy metal enclosure and equipped with an internal 110/220VAC switch selectable linear power supply, the DMM-4 will provide in excess of 100,000 hours of reliable service.
The DMM-4 has a three year warranty and a 24 hour turnaround on warranty repairs from the factory.
| Application | Multiple Sync/Async DCE/DTE devices operating in a polled, contention, or dial environment, to share one DCE/DTE port |
| Capacity | One to Four RS-232 Sync/Async devices |
| Interface | EIA RS-232 CCITT V.24 using DB-25 female connector |
| Data Interface on Delay Ports | Ethernet 10/100/1000 Copper |
| Data Format | Data transparent at all rates |
| Data Rates | Internal: Up to 76.8Kbps
External: Up to 128Kbps |
| Timing | Internal or External |
| Anti Streaming | Automatic…Selectable timeout intervals
Disable…….Selectable via DIP Switch |
| Terminal Service Moeds | Sequential scannong for RTS, DCD or Data |
| Front Panel | Indicators….Power, Transmit Data, Receive data, Channel Active, Channel Stream
Switches…..Enable/Disale of each Subchannel |
| Power Source | 100-120 to 200-220VAC@10%, 50-60Hz, 0.16/0.08A, external
110/220 volt select switch, IEC Power inlet, (2) 5mm Fuses |
| Regulatory Approvals Tested According to | UL 60950-1:2003, CAN/CSA-C22.2 No. 60950-1;2003
FCC Part 15, Class A |
| 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
DMM-4 (Rackmount Model) |
Height ……. 1.75 inches (4.44 cm)Width …….. 17.00 inches (43.18 cm)
Depth ……. 9.00 inches (22.86 cm) |
| Weight | 4.5 pounds (2.1Kg) |
| Warranty | Three years, Return to Base |
| Ordering Information | Model: DMM-4 Description: RS-232 four port Digital Mixing Module |
| 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 |
| Optional Accessories | 1) Spare Data Centre Fuses
A) 160ma Fuse, Qty (2) Part # 714000 B) 80ma Fuse, Qty (2) Part # 714001 |