Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

TIMERSWhen and how to

use them

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

In process controls the timing is often really important; a stable time basis is necessary to sincronyse all the steps of signalling plants (e.g. traffic light plants)

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

Traffic light simulation system

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

it is sometimes possible to measure a quantity, controlling the length of time the action requires (e.g. the radius lift arm which takes the inert materials necessary to produce concrete)

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

Radius lift arm

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

it is sometimes necessary to verify that a certain action is over within the given time or to stop it (time out alarm)

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

Automatic gate

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

TIMERS are tha macro instructions available in every PLC (programmable logic controller) in order to control the processes mentioned before.

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

S_VIMP = timer typeS = set inputTW = time constantR = reset inputT no. = timer numberQ = output timerDUAL = time missing to the end, in Binary codeDEZ = time missing to the end, in BCD code

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

S_EVERZ = timer typeS = set inputTW = time constantR = reset inputT no. = timer numberQ = output timerDUAL = time missing to the end, in Binary codeDEZ = time missing to the end, in BCD code

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

S_SEVERZ = timer typeS = set inputTW = time constantR = reset inputT no. = timer numberQ = output timerDUAL = time missing to the end, in Binary codeDEZ = time missing to the end, in BCD code

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

S_AVERZ = timer typeS = set inputTW = time constantR = reset inputT no. = timer numberQ = output timerDUAL = time missing to the end, in Binary codeDEZ = time missing to the end, in BCD code

Dott. Ing. Alessandro Paganin - I.T.I. Malignani UDINE

BIBLIOGRAPHY:Siemens Simatic Software Ladder Logic Programming manual