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CentreCOM Micro Repeaters

2-Port Fiber Optic Micro Repeaters

Technical Specifications

Choose from:

AT-MR116F	AUI to FOIRL
AT-MR117F	BNC to FOIRL
(Also shown, AT-MR118FT)

Features:

  • IEEE 802.3 compliant repeater, Ethernet Version 1.0 and 2.0 compatible
  • Switch to select either full repeater or half repeater mode
  • Switch for internal 50 W termination for BNC connections
  • Small size allows desktop or wall mount installation
  • Segment partitioning and jabber lock-up protection
  • Status and diagnostic LEDs
  • One year warranty

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These CentreCOM Micro Repeaters are two port media converters designed for the Fiber Optic Inter Repeater Link (FOIRL) to coaxial cable media market place. These micro repeaters allow for connection of an FOIRL segment to either a thinnet (10BASE2) coaxial segment with the AT-MR117F, or to an AUI (10BASE5) coaxial segment with the AT-MR116F. Segments on either side of the unit support full length, fully repeated transmission and allow the maximum number of nodes specified by the IEEE.

These media converters utilize state-of-the-art technologies, including a custom Application Specific Integrated Circuit (ASIC) and Surface Mount Technology (SMT), which provide enhanced functionality, increased reliability and improved performance.

The CentreCOM Micro Repeaters provide the complete functionality of large repeaters, including packet regeneration and network partitioning. Packet regeneration results in a higher performance network by regenerating preamble, retiming the data packets and extending collision fragments to ensure collision enforcement by all nodes.

The use of a proprietary ASIC and an external power supply permits Allied Telesyn to make the CentreCOM Micro Repeaters extremely compact. The units small size allows for the repeater function to be brought to the desktop or used in wall mount installation.

The AT-MR116F (AUI to FOIRL) and AT-MR117F (BNC to FOIRL) have a switch-selection for full repeater or half repeater mode. In the full repeater mode each repeater counts toward the total repeater count specified by IEEE 802.3. In certain situations (i.e. connections between buildings using the FOIRL ports), fully repeated functionality is not needed. The half repeater mode allows a pair of repeaters linking the two networks together to count as one repeater.

Network diagnostic LEDs are provided on the front of the CentreCOM Micro Repeaters to aid in troubleshooting and fault isolation. Both segments have "Transmit," "Receive," "On Line" and "Collision" indicators. All units come with a "Power" indicator and a "Link Integrity Test" LED is provided for the fiber optic port.


Technical Specifications


Front Panel Status Indicators

Per Port:
On Line		Indicates segment is not auto partitioned 
Collision	Indicates collision detected on the repeater
Receive		Indicates a packet is being received from the segment
Transmit	Indicates a packet is being transmitted to the segment 
Fiber Optic: 
Link		Indicates a valid link
Central:
Power		Indicates power is on

Packet Transmission Characteristics

Delay Times:
(Any segment in to other segment out)
		Start of Packet		Collision to Jam
		(Maximum)		(Maximum)
AUI to FO	975 ns 			1175 ns
FO to AUI	1225 ns			1175 ns
BNC to FO	1100 ns 		1250 ns
FO to BNC	1050 ns 		1000 ns
Preamble:
Input		Minimum of 38 bits including SFD
Output		64 bits including SFD 
		(last 2 bits are 1,1)

Jam Output: A pattern of 1,0 is sent to all segments when a transmit collision is detected. This pattern is also sent to the other segment when a receive collision is detected.

Packet Fragment Extension: 96 bits including preamble. Packet fragments are extended using the 1,0 data pattern.

Auto Partition/Reconnection: Each segment will partition itself from other segments if either 32 consecutive collisions occur or if a collision longer than 1 ms occurs. Re-connection occurs after data is transmitted or received without collision on a partitioned port for 512 bit times (IEEE standard algorithm).

Jabber Lock-Up Protection: Packet output is momentarily interrupted for 96 bit times when packet transmission exceeds 64K bits.


Fiber Optic Interface

			Typical			Worst
Optical Wavelength	830 nM			-20 nM 
Optical Saturation	170 µW			150 µW
			(-7.6 dBm)		(-8.2 dBm)
Transmitter:	
Output Power	
	62.5/125 µM	-12.0 dBm		-15.0 dBm	
	100/140 µM	- 6.5 dBm		-9.5 dBm	
	50/125 µM	-16.5 dBm		-19.5 dBm
Receiver:
Sensitivity		-33 dBm (0.5 µW) 	-30 dBm (1 µW)
Saturation		-13 dBm (50 µW)		-14 dBm (40 µW)
Bit Error Rate		Better than 10-10
Flux Budget:
Fiber Size		N/A			Typical
	62.5/125 µM	0.27			13.5 dBm
	100/140 µM	0.30			14.0 dBm
	50/125 µM	0.18			9.0 dBm

Coaxial Interface

Input Impedance			> 100K ohm	
Coaxial Tap Capacitance		< 6 pf
Input/Output Voltage:		Typical		Worst
DC Offset			-0.1 V		-0.5 to 0 V
AC Offset			1.86 Vp-p	1.2 to 2.4 Vp-p
Transmit Rise/Fall Time		25 ns		25 ± 5 ns	

AUI Interface

Parameter:			Typical		Maximum
Signaling Rate			10 Mbps
DI and CI
	Input Impedance		78 ohm		73 to 83 ohm
DO Output Impedance		78 ohm		73 to 83 ohm
DO Output Voltage		900 mV		450 to 1315 mV
DI, CI Threshold Level		160 to 275 mV
AUI Cable Length					50 meters

Thin (BNC) Segments

Type: BNC receptacle with gold center contact for use with BNC type plugs and RG58 thinnet cable. Each segment is connected to an internal 50 ohm terminator (externally switchable).

Internal Transceiver: Complies to the IEEE 802.3 standard.

Segment Length: 0 to 185 meters (RG58) terminated both ends. Maximum of 29 other transceivers on any one segment. (Minimum spacing 0.5 meters between transceivers.)


Power Characteristics

Supply:
Voltage
	AT-MR116F		+5 V ± 5%, +12 V ± 5%
	AT-MR117F		+5 V ± 5%
Current
	AT-MR116F		1.2 A (5 V), 0.5 A (12 V)
	AT-MR117F		1.7 A (5 V)
Power Watts 
	AT-MR116F		12.0
	AT-MR117F		8.5
Ripple				1% (Maximum)

Physical Characteristics

Dimensions			14.0 cm x 11.2 cm x 3.1 cm
				(5.5 in. x 4.4 in. x 1.2 in.)
Weight				0.4 kg (10.0 oz.)
Temperature
	Operating		0° to 50° C
	Storage			-20° to 60° C
Relative Humidity		5% to 80% non-condensing
Electrical/Mechanical Approvals:
EMI				FCC Class A
Safety				UL, CSA, TUV-GS, IEC 825-1 Class 1

Ordering Information

Part Number			Port 1		Port 2
AT-MR116F-X1			SMA		AUI
AT-MR116F-X3			ST		AUI
AT-MR117F-X1			SMA		BNC
AT-MR117F-X3			ST		BNC
Where "X" = 	1 for 110V with U.S. power cord included
		2 for 220V without power cord included

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