The inputs are the manual turnouts commands and the route commands. We have seen that there are five routes and seven turnouts. For the latter, the question arises of the control by two pushbuttons, which is simpler, or by switch, which saves inputs (one per turnout instead of two). Since my module has only twelve inputs, only the second solution is suitable for me.
The outputs are the turnout motor commands, so seven, plus that of the loop reverser relay. Total: eight.
|I1||Turnout hand control A||Q1||Turnout A|
|I2||Turnout hand control B||Q2||Turnout B|
|I3||Turnout hand control C||Q3||Turnout C|
|I4||Turnout hand control D||Q4||Turnout D|
|I5||Turnout hand control E||Q5||Turnout E|
|I6||Turnout hand control F||Q6||Turnout F|
|I7||Turnout hand control G||Q7||Turnout G|
|I8||Route control Voie 1||Q8||Loop relay|
|I9||Route control Voie 3|
|IA||Route control Voie 5|
|IB||Route control Boucle|
|IC||Route control Tiroir|
One immediately sees the limitation of the programmable relay solution: the number of inputs / outputs is very limited. Beyond that, there are complementary modules, but that does not go very far and soon becomes quite expensive. The actual programmable logic controllers (PLC) are much more expensive and more complicated to program, besides the least of the accessories (link cable for example) is overpriced. In this case, it is probably better to switch to the computer control solution.