RS-232 Port Sharing Device

Asynchronous or Synchronous Port Sharing Device - Ideal for Modems or SCADA

Synchronous or asynchronous data 6 ports, RS232 up to 256 Kbps Data is broadcast from composite to all ports Port to composite is RTS/CTS controlled Logical "OR" to composite without RTS control is an available option Active drivers and receivers for extended cable lengths Units can be concatenated for 11, 16, 21 or more ports RTS/CTS port selection takes less than 1 ms Anti-streaming option

FEATURES
DESCRIPTION
SPECIFICATIONS

General
Indicators
Controls
Physical and Electrical

HOW TO ORDER

FEATURES

• Synchronous or asynchronous data
• 6 ports, RS232 up to 256 Kbps
• Data is broadcast from composite to all ports
• Port to composite is RTS/CTS controlled
• Logical "OR" to composite without RTS control is an available option
• Active drivers and receivers for extended cable lengths
• Units can be concatenated for 11, 16, 21 or more ports
• RTS/CTS port selection takes less than 1 ms
• Anti-streaming option

DESCRIPTION

If more that 6 ports are needed, additional MSU-6s may be concatenated. Each additional MSU-6 adds 5 more ports, since one port is given up on the primary unit to support the addition of 5 more ports. Concatenating MSU-6 units adds virtually no delay to the system, as switching is done in less than a millisecond, even when concatenated several units deep.

The MSU has active drivers and receivers on all ports. This insures that the unit exceeds the RS232 minimum cable distances. For example, the RS232 standard for 19,200 bps data is 50 feet of cable. With the active drivers and receivers, users often run cables in excess of 100 feet at 19,200 bps data rates.

When used as a synchronous device, the attached DCE device must be a source of clocking.

The MSU-6 has front panel LED's that show port activity for each port. On the composite, or common channel, there are LED's for Transmit Data, Receive Data and Clear to Send. There is also a power indicator.

Normally used to share one DCE port amongst multiple DTE ports, the MSU may be used in the reverse direction. To share a single DTE port amongst multpile DCE ports, such as broadcasting asynchronous data, see our Asynchronous Sharing Unit, the ASU. The ASU is available in 4, 8, 16, 24, and 32 port units. The data sheet is here.

SPECIFICATIONS

General

• DB-25 female ports (6), RS232, DCE
• DB-25 male composite port, DTE
• Serial speeds from 0 bps to 256,000 bps

Controls and Indicators

• Port activity of each of the 6 ports (CTS)
• Power, Common channel RD, TD, CTS

Physical and Electrical

• 10.25" x 9.75" x 2.5"
• 2.75 LBS including wall transformer
• 9 VDC input, (120 VAC 70 ma external wall transformer supply included at no cost)
• -40 to +70 C operating temperature

Controls

• RTS on the port interfaces are used to select access to the common channel.
• Channels are scanned at a microsecond data rate. RTS/CTS delay is 0 ms.
• Optionally RTS control can be replaced by logical "OR-ing" of all data onto the composite channel
• Anti-Streaming control

Typical Applications

• Connecting a host computer to remote terminals that are polled using asynchronous polling protocols
• Connecting SCADA host computers to RTU's
• Connecting host computers to terminals using synchronous financial industry protocols (HDLC, SDLC, etc)
• Collecting data from multiple data sources into a single remote port

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