User manual SIEMENS DESIGO LONWORKS NETWORKS

[. . . ] 7 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Main characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Influencing factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] LONWORKS distinguishes between: ­ Physical repeaters Straightforward conditioning of the electrical signal only (without neuron chip) ­ Logical repeaters Electrical and logical signal conditioning (timing and checksum) 8 / 24 Siemens Building Technologies LonWorks networks Introduction / Background CA110335en_01 30. 03. 2007 3 Principles For the principles in detail, and guidance on the planning and installation of LONWORKS networks please refer to the relevant installation guides. DESIGO RXC: DESIGO PX: CA110334 Installation guide CA110396, Mounting and installation guide . . 3. 1 · · · · Main characteristics Topology (line or free) Transceiver type (FFT10 or LPT10) relevant for bus supply Number of bus subscribers (nodes) Type of supply. Some third-party devices do not use the same voltages as the Siemens devices, and will require an additional transformer. 3. 2 Influencing factors The characteristics of the network are influenced by the factors detailed below. 3. 2. 1 Topology guidelines The bus topology is determined by the required cable lengths and the structure of the building. 01890en Main bus cable Stubs Building structure Length of stubs from the main bus cables: 9 / 24 Siemens Building Technologies LonWorks networks Principles CA110335en_01 30. 03. 2007 <3m >3m Notes Line topology Freie Topologie In RXC systems, the bus stub is often connected to the room unit. We recommend that this should only be done in cases where access to the LONWORKS network is absolutely essential. · Frequently this results in stubs of more than 3 m, necessitating a free topology. · These additional cables are also susceptible to EMI (they act as antennae for interference). 3. 2. 2 Bus termination guidelines · Line topology 2 bus terminators, 105 each (RXZ02. 1) at each end of the network. · Free topology 1 bus terminator, 520 (RXZ01. 1) at the key point in the network. Note System devices (repeaters and routers) often have a built-in bus terminator with a resistance selector. 10 / 24 Siemens Building Technologies LonWorks networks Principles CA110335en_01 30. 03. 2007 3. 2. 3 Cable length guidelines When deciding on the topology, relevant factors are the maximum cable length and the maximum distance between two bus subscribers. cable length (including cables to room units) 450 m 450 m 500 m 500 m 500 m FTT only 900 m 900 m 900 m 1400 m 2700 m Max. distance between two devices (nodes) 250 m 250 m 320 m 400 m 500 m FTT & LPT No info No info 750 m 1150 m 2200 m . _ _ _ Free topology Category 5 ConCab JY(St)Y 2x2x0. 8 Level IV Belden 8471 Line topology Category 5 ConCab JY(St)Y 2x2x0. 8 Level IV Belden 8471 If shielded cable is used, the shield must be capacitively earthed (connected to ground) at least once per segment. In the event of a high level of interference, this may be required at each node. If LPT-10 nodes (QAX5. . ) and bus power supply are used, the DC power consumption of the LPT nodes must be taken account of when designing the cable length and cross section (line resistance). The cable length can be doubled by use of a physical repeater. STOP Caution No more than 1 physical repeater may be connected in series. 01891 max. cable length 11 / 24 Siemens Building Technologies LonWorks networks Principles CA110335en_01 30. 03. 2007 3. 2. 4 Guidelines on the number of bus subscribers The relevant factor here is the number of bus subscribers per physical segment or channel. A physical segment is a continuous section of the LONWORKS network, uninterrupted by repeaters, routers or gateways. Routers, PC-based tools and the PXR itself are also bus subscribers. 14 / 24 Siemens Building Technologies LonWorks networks Principles CA110335en_01 30. 03. 2007 4 4. 1 Activity Max. cable length for Category 5 cable or ConCab Empirical design values Free topology Recommendation 250 m Practical experience and comments The actual cable length is difficult to estimate. The maximum length of 450 m is subject to an ideal installation in compliance with all the regulations (see Section 6). . . Regulations 450 m Clearance between two furthest nodes Location of bus terminators 1 x 52 1 x RXZ01. 1 250 m 250 m This limitation is often forgotten. This varies from project to project and there is not always an ideal location (e. g. [. . . ] Variable speed drives, for example, are a possible cause of this kind of interference. STOP Caution Do not use if the signal level or signal shape are not correct. 23 / 24 Siemens Building Technologies LonWorks networks Checklist for handover of the installation CA110335en_01 30. 03. 2007 8 Signal level too low Troubleshooting · Wrong bus terminator (e. g. the built-in bus terminator in a repeater or in a bus power supply may have been forgotten) · A high-level signal indicates signal reflections or that there is no bus terminator or the wrong bus terminator. · Bus terminator in wrong place Find the key point in the network by trial and error · Faulty bus power supply Disconnect the LONWORKS network from the bus power supply and measure the no-load voltage of the bus power supply (38. 5V to 42. 6V DC). Failure to observe the installation guidelines or cable type specification Connect an additional repeater and another bus power supply Important note: Only one bus power supply may be connected per physical segment · Load too high (max. [. . . ]