MT-RJ Optical Fiber System Field Testing
Table of Contents INTRODUCTION... 3 TEST JUMPERS... 4 LAUNCH CONDITIONS... 4 MT-RJ TEST KITS... 5 MT-RJ SYSTEM TESTING: Fixed transmit and receive (SC or ST-style) ports... 6 MT-RJ SYSTEM TESTING: Fixed transmit (SC or ST-style) and interchangeable receive ports... 9 CALCULATE SYSTEM LOSS... 12 CONCLUSION... 12 2 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved.
INTRODUCTION This paper describes two field test procedures for the MT-RJ optical fiber system. ANSI/TIA-568-C.0, Generic Telecommunications Cabling for Customer Premises, currently recommends the one jumper reference test method. This procedure is described in TIA/EIA-526-14A, method B, Optical Power Loss Measurements of Installed Multimode Fiber Cable Plant, and TIA/EIA-526-7, method A.1, Measurements of Optical Power Loss of Installed Single-mode Fiber Cable Plant. These documents use procedures that assume the test equipment has the same connector interface as the patch panel and outlet. This can be a problem when testing a fiber network that uses a different connector type other than the test equipment interface ports. While Dual-fiber designs such as the MT-RJ are a popular installation choice, a majority of the test equipment in use today have fixed transmit and receive ports with SC or ST- style connectors. In these cases, the one jumper reference measurement procedure must be slightly modified to test the MT-RJ system. The MT-RJ connector presents other unique testing challenges simply because it is a fixed duplex (2 fiber) connector. To properly test the MT-RJ system with the recommended one jumper reference method, test units with fixed transmit ports and an interchangeable receive port with a MT-RJ interface are required. In an effort to clarify these procedures, this paper will describe the necessary steps for MT-RJ system testing with equipment using: - Fixed transmit and receive ports other than MT-RJ (SC or ST- style) - Fixed transmit (SC or ST- style) and interchangeable receive ports that include MT-RJ 3 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved
TEST JUMPERS To ensure accurate and repeatable test results, quality test jumpers must be used during testing. It is essential that proper test jumpers are maintained with proper cleaning techniques throughout testing. More often than not, high losses experienced during testing are a result of poor quality test jumpers. AMP NETCONNECT offers test kits comprised of quality jumpers in the proper configuration and fiber type for use with SC, ST- style, or MT-RJ interface test equipment. These kits are available to test either standard MT-RJ or MT-RJ SECURE systems. Additionally, individual jumpers are available to replace jumpers if they become damaged or worn after repeated use. LAUNCH CONDITIONS Another important factor in obtaining accurate and repeatable results is the launch condition on the source. ANSI/TIA-568-C.0 and ISO 11801, as well as AMP NETCONNECT, recognize the importance of a conditioned launch by recommending the use of mandrel wraps during the reference set up and the actual test. Multimode optical fiber may appear to have higher than expected attenuation due to the power loss in the high-order modes. To remove the high-order mode transient losses from the multimode optical fiber measurements, the reference jumper should be wrapped in five non-overlapping turns around a smooth mandrel during the reference calibration and for all loss measurements. The mandrel diameter depends on the fiber core size and also the specification being followed. Below is an illustration of the mandrel wrap using the mandrels supplied in the test kits: 50/125um IEC 50/125um ANSI/TIA-568 62.5/125um IEC and ANSI/TIA-568 4 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved.
MT-RJ TEST KITS Equipment Transmit Port Fiber Type Part Number ST-Style SC 50/125um 1278861-2 62.5/125um 1278862-2 Single-mode 1278863-2 50/125um 1278861-1 62.5/125um 1278862-1 Single-mode 1278863-1 Test Kits for the MT-RJ SECURE connector system are available through your local AMP NETCONNECT Sales Engineer. Replacement Components for MT-RJ Test Kits Connector End 1 Unpinned MT-RJ Pinned MT-RJ Connector End 2 Unpinned MT-RJ SC ST-Style SC ST-Style Fiber Type Part Number 50/125um 6435096-2 62.5/125um 6435096-1 Single-mode 6435096-3 50/125um 6435092-2 62.5/125um 6435092-1 Single-mode 6435092-3 50/125um 6435094-2 62.5/125um 6435094-1 Single-mode 6435094-3 50/125um 6435092-5 62.5/125um 6435092-4 Single-mode 6435092-6 50/125um 6435094-5 62.5/125um 6435094-4 Single-mode 6435094-6 MT-RJ to MT-RJ Coupler 1278017-1 Mandrels, set of two, 50/125um type 1435119-2 Mandrels, set of two, 62.5/125um type 1435118-2 Each Test Kit includes: 1 MT-RJ Coupler 2 MT-RJ (no pins) to SC Simplex or ST-style Cable Assemblies 1 MT-RJ (with pins) to SC Simplex or ST-style Cable Assembly 1 MT-RJ to MT-RJ Cable Assembly 2 Mandrels (not included with Singlemode Kit) 1 Carrying case For XG fiber testing, use standard 50/125um Multimode products 5 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved
MT-RJ SYSTEM TESTING Fixed transmit and receive equipment ports other than MT-RJ (SC or ST- style) Step 1 Verify the test leads are in good condition and are continuous for all fiber paths. If there is any doubt about the cable assembly, or if test results are erratic or unusually high, replace the assembly before conducting any testing. Replacing reference test leads after a reference value has been obtained requires a new reference measurement before further testing. Install the mandrel on the transmit (Tx) leg (both A or both B sides) of the cable assemblies by applying five non-overlapping wraps around the mandrel (Figure 1). Maintain this mandrel wrap during the reference and the test. The cable assembly can be held in place by installing a cable tie through the center hole in the mandrel and around the cable. Ensure the cable tie is not tightened to the point of compressing the jumper cable jacket. Step 2 Connect the pinned MT-RJ to SC or ST- style jumper and the unpinned MT-RJ to SC or ST- style jumper to the test units. Make sure the SC or ST- style connector polarity is correct (transmit to receive or A (Tx) to B (Rx) connection) (Figure 1). 6 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved.
Tx Rx Tx Rx Figure 1 Step 3 Connect the two jumpers with the MT-RJ coupler (Figure 1). Record two power values, P1 and P2, one for each fiber path. These values are the Reference values for subsequent testing. Note: record all power values in dbm (or store values in equipment as reference values). Make sure the jumper fiber type matches the system fiber type under test. 7 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved
Step 4 Disconnect the unpinned MT-RJ from the coupler, and insert this plug into the jack of one end of the Cable plant under test (Figure 2). Connect a standard (without pins) MT-RJ to MT-RJ jumper (MM) between the pinned MT-RJ test lead and the jack of the other Cable plant end. Record two power values, P1 and P2, one for each fiber path. Note: record all power values in dbm (most equipment will store these values and automatically calculate system link loss). Go to the Calculate System Loss section of this document to calculate the acceptable system loss. Tx Rx Tx Rx Figure 2 8 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved.
MT-RJ SYSTEM TESTING Fixed transmit (SC or ST-style) and interchangeable receive port (MT-RJ, SC, or ST- style) Step 1 Verify the test leads are in good condition and are continuous for all fiber paths. If there is any doubt about the cable assembly, or if test results are erratic or unusually high, replace the cable assembly before conducting any testing. Replacing reference test leads after a reference value has been obtained requires a new reference measurement before further testing. Two unpinned MT-RJ to SC or ST- style assemblies are used as reference cables in this setup. Install the mandrel on the transmit (Tx) leg (both A or both B sides) of the cable assemblies by applying five non-overlapping wraps around the mandrel (Figure 3). Maintain this mandrel wrap during the reference and the test. The cable assembly can be held in place by installing a cable tie through the center hole in the mandrel and around the cable. Ensure the cable tie is not tightened to the point of compressing the jumper cable jacket. Step 2 Connect the MT-RJ to SC or ST- style jumpers to the test units (Figure 3). Make sure the mandrel leg is connected to the transmitter (Tx). Install a MT-RJ removable receptacle adapter to the receive (Rx) side of both test units. Plug the MT-RJ connector into the receive (Rx) side of the other test unit as shown in Figure 3. 9 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved
Tx Rx Tx Rx Figure 3 Step 3 Record two power values, P1 and P2, one for each fiber path. These values are the Reference values for subsequent testing. Note: record all power values in dbm (or store values in equipment as reference values). Make sure the jumper fiber type matches the system fiber type under test. Step 4 Disconnect the MT-RJ connectors from the test units (Figure 4). Replace the MT-RJ receptacle caps with SC or ST- style adapter caps. Connect the SC or ST- style connectors that were not used in the reference measurement to the Receive (Rx) side of the test units. Connect the MT-RJ plugs to the Cable plant. Record two power values, P1 and P2, one for each fiber path. Note: record all power values in dbm (most equipment will store and automatically calculate system link loss). Go to the Calculate System Loss section of this document to calculate the acceptable system loss. 10 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved.
Tx Rx Tx Rx Figure 4 11 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved
CALCULATE SYSTEM LOSS Calculate system loss for each fiber by subtracting the system power values from the system reference values. Calculate the maximum allowable system loss by summing the maximum cable attenuation, connector attenuation, and splice loss for the link under test. LOSS system = LOSS cable + LOSS connector + LOSS splice Where: LOSS cable = Attenuation Coefficient [db/km] x Cable Length [km] Maximum Attenuation Coefficient for Cable (ANSI/TIA-568 and ISO 11801 except where noted) 3.5 db/km @ 850nm for multimode (50/125um, XG 50/125um, and 62.5/125um) 1.5 db/km @ 1300nm for multimode (50/125um, XG 50/125um, and 62.5/125um) 0.5 db/km @ 1310nm for single-mode outside plant cable for ANSI/TIA-568 0.5 db/km @ 1550nm for single-mode outside plant cable for ANSI/TIA-568 1.0 db/km @ 1310nm for single-mode outside plant cable for ISO 11801 1.0 db/km @ 1550nm for single-mode outside plant cable for ISO 11801 1.0 db/km @ 1310nm for single-mode inside plant cable 1.0 db/km @ 1550nm for single-mode inside plant cable LOSS connector = Number of Connector Pairs x Connector Loss [db] Maximum Connector Loss (each): 0.75 db LOSS splice = Number of Splices x Splice Loss [db] Maximum Splice Loss (each): 0.3 db To be eligible for a 25-year warranty, the calculated system loss must be less than or equal to the maximum allowable system loss published in the current AMP NETCONNECT System Warranty. CONCLUSION These test procedures verify the attenuation and polarity of the installed MT-RJ system using common field test equipment. AMP NETCONNECT s MT-RJ test kits contain all the components and assemblies for both test configurations. 12 Copyright 2009 Tyco Electronics Corporation. All Rights Reserved.