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Installing the Modem

 

Jumper S10 

 Carrier Detect Delay 

 

Settings: 

6 ms (

default

23 ms

 

Jumper 

S10

 configures the modem’s Carrier Detect turn on Delay timing. The delay chosen must be consistent with 

the Clear To Send delay selection of the transmitting modem and must be less than the CTS delay. The available 
delays are 6 ms (default) and 23 ms. The carrier detect drop out is less than 6 ms. 

Jumper S11 

 Turnaround Squelch Time 

 

Settings: 

8 ms (

default

159 ms

 

Jumper 

S11

 is used with the call turnaround squelch option (jumper 

S4

). The available times are 8 ms (default) and 

159 ms. 

Jumper S12 

 Soft Carrier Turn Off 

 

Settings: 

None 
8 ms (

default

26 ms

 

Jumper 

S12

 configures the modem to either turn off the transmitter immediately upon release of Request To Send, 

or send a Soft Carrier Turn Off signal of 900 Hz for 8 or 26 ms at the end of each transmission. 

Jumper S13 

 Anti-Streaming 

 

Settings: 

None (

default

4 seconds 
7.6 seconds 
14 seconds 
28 seconds 
56 seconds

 

Jumper 

S13

 lets you select an anti-streaming time or use no anti-streaming at all. Anti-streaming is typically used in 

multi-point applications to prevent a malfunctioning slave from occupying the line indefinitely.   

When anti-streaming is active, the modem can only transmit data for up to 56 seconds. Thereafter, the modem’s 
transmitter is automatically turned off. The modem then looks for an ON-to-OFF transition of Request To Send 
(RTS) before proceeding with normal operation. 

Page 11 

Содержание MD1970A

Страница 1: ...February 2004 0049 0119 500 MD1970A MD1970A DC MD1970C Modem...

Страница 2: ...or Test Pattern 12 CONNECTING A DTE 12 CONNECTING TO A PRIVATE LINE COMMUNICATION CIRCUIT 12 Connecting to a DC Power Source MD1970A DC 12 Connecting to an AC Power Source MD1970C 13 CHAPTER 3 LEDS A...

Страница 3: ...s for power RS 232 control data status and test mode Models The BLACK BOX modems are available in three models The MD1970A is a desktop modem that comes with an AC power adapter for 115 230 VAC The MD...

Страница 4: ...ware Your package should include at least one MD1970A or MD1970C modem one RJ 45 jack to 4 wire leased line cable and this Installation Guide If your package contents are damaged or missing please con...

Страница 5: ...input connector A power switch for turning the modem on and off A fuse 3 8 amp 250 Volt slow blow A DB25 female connector for accommodating a DTE device An RJ 45 connector for connecting to a communic...

Страница 6: ...nge the default jumper settings To change jumper settings push the two tabs on the back of the modem to open the modem cover and gain access to the jumper settings on the printed circuit board see Fig...

Страница 7: ...Installing the Modem Figure 2 5 Modem Jumper Locations Page 7...

Страница 8: ...und Connected Separate 10 S9 RTS CTS delay 8 ms 33 ms 59 ms 219 ms 10 S10 Carrier Detect delay 6 ms 23 ms 11 S11 Turnaround squelch time Enabled by jumper S4 8 ms 159 ms 11 S12 Soft Carrier turn off N...

Страница 9: ...to maintain constant carrier from the master modem to all slave modems at all times after the initial training This enables the master modem to transmit data to the slave modems with no RTS to CTS de...

Страница 10: ...s the default position of Disabled when operating on a 4 wire network It is also normally left in the default Disabled position when operating on a 2 wire network Strapping this jumper as Disabled inh...

Страница 11: ...8 ms default 26 ms Jumper S12 configures the modem to either turn off the transmitter immediately upon release of Request To Send or send a Soft Carrier Turn Off signal of 900 Hz for 8 or 26 ms at the...

Страница 12: ...wn under Telco Connector on page 19 Connecting to a DC Power Source MD1970A DC The MD1970A DC back panel accepts a DC voltage source from 10 to 53 VDC and provides 500 Volts isolation Figure 2 3 on pa...

Страница 13: ...making this connection to the modem align the power adapter with the positive and negative markings on the modem rear panel Powering on the Modem To supply power to the modem place the POWER ON switch...

Страница 14: ...ransmitter output of the modem is disconnected from the output coupling transformer and connected to the modem receiver input See Figure 3 1 DL Digital Loopback this position configures the modem to l...

Страница 15: ...r are active during this mode Figure 1 Analog Loopback Test DTE DTE RECEIVER TRANSMITTER PAD TRANSMITTER RECEIVER Local Modem Analog LoopBack Mode RXD TXD 4 Wire Telephone Line Remote Modem Data Mode...

Страница 16: ...re Telephone Line Self Test TM TX RX Amplifier Figure 3 3 Self Test DTE DTE TEST PATTERN TRANSMITTER ERROR CHECK RECEIVER Local Modem Send Test Pattern Mode 2 Wire Telephone Line Remote Modem Receive...

Страница 17: ...e front panel test switch place the modem in Self Test mode 2 The TM indicator should turn ON If the indicator turns OFF or flashes errors are occurring Line and Modem Test The line and modem test ver...

Страница 18: ...to 14 dBm in 2 dB steps RTS CTS delay 8 33 59 or 219 ms Carrier Detect delay 6 or 23 ms OFF to ON 6 On to OFF Digital interface EIA RS 232 C and CCITT V 24 Package Standalone UL approved Turnaround sq...

Страница 19: ...Circuit CCITT V 24 Circuit Function 1 AA 101 Protective Ground 2 BA 103 Transmitter Data 3 BB 104 Receive Data 4 CA 105 Request to Send 5 CB 106 Clear to Send 6 CC 107 Data Set Ready 7 AB 102 Signal G...

Страница 20: ...registration number Items b and d can be found on the unit s FCC label The ringer equivalence number REN is used to determine how many devices can be connected to your telephone line In most areas the...

Страница 21: ...the specifications in Subpart B of Part 15 of FCC rules which are designed to provide reasonable protection against such interference when the equipment is operated in a commercial environment Operat...

Страница 22: ...rato 12 Precauci n debe ser tomada de tal manera que la tierra fisica y la polarizaci n del equipo no sea eliminada 13 Los cables de la fuente de poder deben ser guiados de tal manera que no sean pisa...

Страница 23: ......

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