UDS 202T Modem

DC&AC power modem
202T Frequency Shift Keyed (FSK) modem

UDS 202T (202S 202S/T in pre-owned) - 
desk top and rack cards - 
AC power and 12 to 60 DC power 202T modem 
"new and used units" in stock 

The UDS/Motorola 202T modem features built-in diagnostic and anti-streaming capabilities and the anti-streaming capability prevents a modem from remaining in the transmit mode when the modem is not actively transmitting data. 

Diagnostic features allow the user to verify transmitted and received data

  • Stand Alone 202T    62025197

  • Rack Card 202T      62025209

  • DC Powered 202T    62025299

Motorola is back in production again on the 202T modems - desk tops, DC power and rack cards - now you can plan for future networks using the Motorola 202T modems.

We have units in stock

We also have 202S and 202S/T 202S/D in used
see 202S/T and 202S/D page

check out Racal Vadic site for new 202S

jump to 202 realted pages

jump to DC Modem page Bell 103, 212, V.22, V.32, V.34 V.29

You  may also want to consider pre-owned communications gear!

UDS 202T
DC&AC power modem
202T Frequency Shift Keyed (FSK) modem



The UDS 202T modem features built-in diagnostic and anti-streaming capabilities. The anti-streaming capability prevents a modem from remaining in the transmit mode when the modem is not actively transmitting data. The diagnostic features allow the user to verify transmitted and received data. The specific features are.

202T_120_JPG.jpg (12272 bytes)
  • 2-wire half duplex or 4-wire full duplex private line operation 
  • 0 to1200 bps data rate over unconditioned lines and 1,800 over high quality lines
  • Antistreaming
  • Phase coherent, frequency shift keyed (FSK) modulation
  • LED indicators
  • Front panel rotary switch function selector
  • Integral test features

The Universal Data Systems 202T is a Frequency Shift Keyed (FSK) modem which is designed for asynchronous operation at 0 to 1800 bps with C2 line conditioning, or 0 to 1200 bps asynchronous operation on unconditioned lines. The modem provides half duplex communications on 2 wire private lines or full duplex communications on 4 wire private lines, and is ideal for use in multipoint networks.

The 202T is a single printed circuit card enclosed in a new compact size housing. The unit features an integral anti-streaming protection option which prevents network Tie-ups by incorporating a delay timer that will disconnect a modem, if it remains in transmit mode longer than a selectable period of time. The 202T also features strap options for Request to-Send/Clear to Send Delay timing, Transmit Carrier, local Copy Squelch, Turnaround squelch, Soft Carrier Turn Off, Carrier Detect Level, Carrier Detect Delay, and Test Generator Baud Rate Select. These strap options allow the user greater control of the modem, for his individual application.  

 The UDS 202T standalone modem is designed to be interchangeable between the Universal Data Shelf multiple modem enclosure and the stand alone modem enclosure. By removing the modem card and attaching the optional front panel, the modem can be directly inserted into the Universal Data Shelf. With this feature, a data-communications facility can be easily upgrade front multiple standalone enclosures to a centralized rack without the expense and trouble of purchasing new modems.

Additionally a single 202T may be mounted in a standard 19" equipment rack via the UDS models RM16M Model 1 through model 29.  


Data Rate: 0 to 1200bps asynchronous over unconditioned  lines

Operation: Full duplex over 4 wire private lines or half  duplex over 2-wire private lines

Modulation: Phase coherent, frequency shift keyed (FSK)

Carrier Frequencies: Mark: 1200 Hz Space: 2200 Hz

Line Impedance: 600 ohms 10% transformer coupled and transient protected

Transmitter Output Level: Selectable from 0, to -12
dbm in 2 dbm steps

Clear to Send Delay: 8.3 ms, 33.2 ms, 59.9 ms, or 219.6 ms (selectable)

Carrier Detect Delay: 6 ms or 23 ms

Digital Interface: EIA RS-232 (DB-25 female) and CCI1l V.24

Teleco Interface: RJ45 female

Turnaround Squelch: 0 ms, 8.3 ms, or 159.6 ms

Antistreaming: 4, 7.6, 14, 28, 56, none (selectable)

Soft Carrier Turnoff: 0 ms, 8.3 ms, or 26.6 ms

Environmental: 0 to 50 C; 95% humidity, noncondensing          

Mechanical: Width: 7"; Height 2.25"; Depth: 9.60"; Weight  3.0 Lbs.

AC Power Requirement:115 VAC single phase,  47 to 63 Hz @ 10 watts maximum

DC Power Requirements: 12 to 60 VDC

Certification: FCC Rules, Part 15 certified, CSA certified, DOC certified


Test Operate Switch

DL (Digital Loopback); When the switch is in the ST position, the received data is looped back into the transmitter and the data is transmitted to the remote end. The modem must be in the 4 wire mode.

TTP (Transmit Test Pattern): When the switch is in the TTP position, the transmitter is forced ON and transmits the date from the dot pattern generator to the COMM Line. The RS-232 interface lines to the transmitter are not active (RS, CS, TD).

DATA: The switch must be in the DATA position for all normal data transmission Indicators

RS (Request to Send): is illuminated when the RS line is high (ON)

CS (Clear to Send): ON when the CS line is high (ON)

CD (Carrier Detect): ON when a carrier is detected by the modem receiver.

RD (Receive Data): On when data is received, decoded, and furnished to the terminal equipment. RD is also ON when the receive cats line goes into a space condition, OFF in a mark condition.

TD (Transmit Data): Responds in the same manner as the RD LED, but only when data to be "transmitted" is furnished to the modem. However, the LED may be on when the DTE is disconnected.

TM (Test mode): Active when Test switch is in any test mode. The indicate' will blink OFF/ON when errors occur in Self Test mode

POWER: ON when power is applied to the modem.

301-924-7400 EXT 25

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