Olson Technology MUSCLE-EM55X - Manual (Page 69)

OTOT-EM55X/XL Optical Transmitter Rev. x1 www.olsontech.com
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and optical switches) provide two RS485 slave interfaces on the rear side of the equipment. The two RS 485 interfaces
are typically used for daisy chaining the RS485 interface bus.
There are some limitations to be considered for a proper functioning of the EMS-server:
• Physical limitations: For the RJ-45 cable a CAT6 or better data cable is recommended. The length of the cable
should be chosen as short as possible. A distance of 10 m should not be exceeded anyway.
• General limitations: A maximum of 48 devices can be managed by one NEC.
• In order to get a correct display of the “rackview” function of the NEC, there are two more limitations required:
• All devices to be managed by one NEC have to be positioned in one rack (and on one side of the rack if the rack
is equipped with equipment from both sides).
• A maximum of four subracks can be used. The address of all subracks have to be set correctly by adjusting the
decimal switches located on the interface panel of the subracks. Address “1” has to be used for the upper sub
rack, the next following sub rack will obtain address “2” and so on.
After powering up, the NEC will poll all equipment connected to the RS485 interface automatically. It might take up
to about 2 minutes until all equipment have been identified. This is also true if equipment is removed or added during
normal operation of the NEC.
Maintenance
• Clean connector ends with a lint free tissue and alcohol before every mating.
• Loose screws fixing the optical connector plate
• Remove the connector from the connector bulkhead.
• Clean the connector ends with a lint-free tissue and alcohol.
• Reinstall the connector into the bulkhead ensuring that the cables/fibers are not stressed.
• Caution: Do not extend the connector by more than 1 cm from the body of the OTOT-EM55X.
Troubleshooting
To avoid problems with the OTOT-EM55X and 1550nm transmission, follow these general rules:
• Use only carefully cleaned angled connectors like SC/APC, FC/APC, E2000 and similar ones for the whole
transmission system between optical transmitter and receiver. A mix of angled and non angled connectors will
result in high insertion loss, and a degradation of the CSO and CNR performance.
• Avoid bending losses of fibre optic cables. Since optical transmission on 1550 nm significantly more sensitive
to bending losses it is very important to avoid narrow curvatures
• Use a proper levelled, flat RF-input signal. The flatness of the input signal (e.g. ±1 dB) will directly result in the
same variation of CNR, CSO and CTB (in this example: ±1 dB).
• Be careful to understand all nonlinearities in optical fibres with 1550 nm transmission, long distances and high
optical powers. CNR and CSO can easily degraded due to self phase modulation and Brillouin scattering. In
doubts check the performance of the link by using an optical attenuator instead of using optical fibre to see
whether the performance is limited due to impacts from the fibre.
• In case of technical questions please ask our sales representative.
• Note: Since the transmitter is working internally with very high optical power and microwave signals it is
not admitted to open the transmitter for personal safety and EMC reasons. Do not open the transmitter!
In case of other than fan/power supply failures the transmitter has to be sent to Olson Technology for
maintenance!
End of Manual