DMM‐4880 & DMX‐4880 Instruction Book Revision 0
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Technical Specifications
DMM‐4880:
Inputs:
Type 1 4 x STM‐1 (OC‐3), 75Ω, 1Vp‐p, BNC connector.
Electrical Characteristics CMI encoded.
Data Rate 155.52 Mb/s.
Equalisation Automatic, > 200m at 155Mb/s for Belden 8281 or equivalent cable.
Type 2 (Optional) 1 x optical STM‐4 (OC‐12), LC/PC (standard) optical connector.
Optical Characteristics NRZ encoded.
Data Rate 622.08 Mb/s.
Output:
Type 1 x optical STM‐4 (OC‐12), SC/PC (standard) optical connector1.
Optical Characteristics NRZ encoded.
Data Rate 622.08 Mb/s.
Alarm Output: MAJOR Not used. Open circuit on loss of power.
MINOR Open circuit on no valid input STM‐1 streams present, or loss of power.
DMX‐4880:
Input:
Type 1 x STM‐4 (OC‐12), optical, SC/PC optical connector (standard).
Optical Characteristics NRZ encoded.
Data Rate 622.08 Mb/s.
Outputs:
Type 4 x STM‐1 (OC‐3) 75Ω, 1Vp‐p, BNC connector.
Data Rate 155.52 Mb/s.
Alarm Output: MAJOR Open circuit on no valid STM‐4 input present, or loss of power.
MINOR Open circuit on no valid output STM‐1 streams present, or loss of power.
Optical
Optical path loss23 to 18 dB with PIN detector (typically 20dB),
Optical fibre Designed for use with 9/125 μm single mode fibre.
Optical wavelength 1310nm (DFB laser ‐standard).
Optical connectors SC/PC (standard).
DMM‐4880 optical output 0 dBm +3/‐0 dB standard DFB laser,
DMX‐4880 optical input PIN detector, ‐3 to ‐18 dBm input level
Power Requirements 28 Vac CT (14‐0‐14) or ±16 Vdc.
Power consumption 7 VA.
Other
Temperature range 0 ‐50° C ambient.
Mechanical Suitable for mounting in IRT 19" rack chassis with input, output and power
connections on the rear panel.
Finish Front panel Grey background, black lettering & red IRT logo.
Rear assembly Detachable silk‐screened PCB with direct mount connectors to Eurocard and
external signals.
Dimensions 6 HP x 3 U x 220 mm IRT Eurocard.
NOTE: 1 If optional STM‐4 reference fitted, standard output optical connector is an
LC/PC type.
2Optical attenuator required for optical paths <3dB optical loss.
Due to our policy of continuing development, these specifications are subject to change without notice.
