Poll Remote | The
timing by which the Central Hydrological System gathers data from a
remote outstation |
Poll Types | SEPA
Normal Poll – Data values requested from the remote
outstation once every 24 hours. SEPA Normal Poll – Data values requested from the remote outstation once every 24 hours. SEPA Event Poll – Data values requested from the remote outstations once every 60 minutes for a period of 2 days. SEPA Alarm Dial Up – The alarm condition messages which are reported from the remote outstations on occurrence. DARDNI Normal Poll – Data values requested from the remote outstations once every 7 days. DARDNI Voice Message Poll – Telephone calls made to the remote outstations which generate automated voice messages which provide the status and values of the measured hydrometric items on a particular site. |
Protocol | The structured method by which data is retrieved from a site. Generally each remote outstation supplier provides their own proprietary communications protocol. |
DNP3 | A new standard protocol which can be used across a wide range of remote outstations from different suppliers. |
PSTN | Public switched telephone network |
GSM | Second generation mobile phone networks |
GPRS | General Packet Radio Service – provided on mobile phone networks. |
TG1150 | The existing remote outstation type used within SEPA |
D7000 | A new range of remote outstations which SEPA are assessing for the future. |
Data Logger | A particular type of remote outstation used for on site recording of data. SEPA have a number of Dynamic Logic TG 1150 outstations and Isodaq data loggers and DARDNI have a number of OTT data loggers. |
Portability | A term used to describe the capability of equipment to deployed and then re-deployed as required at different sites. |
Baud Rate | The data transfer rate from the remote outstation to the central gathering system measured in digital bits per second. |
Instrument | The field device which is used to measure the required site data, such as river flow, river levels, water quality and rainfall. |
Geo-referencing | Assigning co-ordinates to an image file, usually by inputting the co-ordinates of known or prominent features. |
NPV | This is the summation of the 15-year life cycle annual stream of discounted total costs, for each communication technology, giving the equivalent total value for today. This is done by discounting the 15-year life cycle annual costs using an appropriate discount rate, which for this project will be 3.5%. |
CDMA | Code Division Multiple Access: A technology for digital transmission of radio signals between, for example, a mobile telephone and a radio base station. In CDMA, a frequency is divided into a number of codes. |
SWOT | An Options Analysis process. The SWOT methodology allows the strengths, weaknesses, opportunities and threats to be listed and then compared. |
Energy density | The
energy density of a battery is the amount of energy a kilogram weight
of a battery could deliver, it is expressed in watt-hours per
kilogram (Whr/Kg). |
Discharge rate | The discharge rate of a battery is often expressed in terms of the C-rate. This is the current drain that would discharge a battery in one hour. This would, usually, be a very high load to impose on a battery and effects characteristics such as the discharge curve so most battery manufacturers provide data for a reduced discharge rate of 0.2C or 0.1 C. Consequently care is needed when comparing data from different manufacturers. |