AL16AN Programmable Logic Controller Instruction ... - FF-Automation

Page 6 - 230/05/99AL16AN Instruction ManualExpansion boards AL 32EX, AL 32EXA receive their +5 V supply voltage from thebasic board through the ribbon cable. The expansion boards further require a +15 Vsupply, which is generated on the expansion board from +24 V DC wired from the basicboard to the terminal strip of the expansion board.The expansion board AL32EXOreceives + 5 V supply voltage from the basic board, the 24 VDC voltage for loads mustbe wired from external power supply unit.The +24 V DC supply voltage to the relay output boards is taken from an externalpower supply unit. The RE 16 board further requires a connection to the VDIODEterminal of the basic board.6.2.3 Digital inputsThe digital inputs are unisolated in AL16 PLC series. Only potential free contacts orNPN type inductive/capacitive sensors may be connected to PLC. The supply voltagefor the NPN sensors is normally taken from PLC's terminals.It is recommended to usetwisted pair shielded cables in input wiring. The cabling should be installed separatefrom the 220/380 VAC power cabling. The cable shields may be connected to logicground only at one point, normally at the end on the PLC encloseure.If there is heavyelectromagnetic disturbances, the PLC's inputs and outputs can be isolated from fieldequipments with relays or with optoelectronics modules. Look at chapter 6.3.26.2.4 Digital outputsThe digital outputs are unisolated in AL16 PLC series. Only lowpowered 24 VDCcontrol relays, LED indicating lights or 24 volt indicating lights may be connected toPLC. The supply voltage for loads is taken from PLC's supply pwer unit.It is recommendedto use twisted pair shielded cables in output wiring. The cabling should beinstalled separate from the 220/380 VAC power cabling. The cable shields may beconnected to logic ground only at one point, normally at the end on the PLCencloseure.If there is heavy electromagnetic disturbances, the PLC's inputs andoutputs can be isolated from field equipments with relays or with optoelectronicsmodules. Look at chapter 6.3.26.2.5 Analog inputs/outputsThe analog inputs and outputs are unisolated in AL32 PLC series. If the usedtransmitters are active, they have their own separate supply connection and if theoutputs from the transmitters are unisolated from their supply power, it is recommendedto use galvanic isolators in connections. The galvanic isolators may be eitherpassive or active. The input inpedance of analog input of AL32 series is 250 Ω. Therecommended cable type in analog connections is twisted pair shielded cable.Thecable shields may be connected to logic ground only at one point, normally at the endon the PLC encloseure.FF-Automation Oy