Mettler Toledo IND310drive Manual De Instalación página 28

IND310drive Installation Manual
COM1 Current Loop
Current loop systems use flow of current to transmit digital information. There are
two types of 20 mA current loops: Active and Passive. Active systems have the
current/voltage source built into the circuit. Passive systems require an external
current/voltage source to complete the circuit. Normally one side of the current loop
is active and the other passive. Two active current loop systems cannot be
connected together.
The IND310drive current loop is a "passive" current loop system, that is it does not
have a current or voltage source built in; however, the COM1 connector supplies a
+12V source to activate the system. The advantage of this arrangement is that the
IND310drive can be connected to a passive peripheral by using the +12V source
on the COM1 connector or to an active peripheral by connecting the +20mA and
−20mA lines to the respective lines of the peripheral.
Figure 2-11 shows how to connect the IND310drive current loop to a passive and
an active peripheral. Note that for a passive peripheral it is necessary to jumper pin
3 and pin 5 on J15 of the IND310drive main PCB.
2-10
Table 2-5: Com 2 Port on Main Board
J16 Pin
Number
1
2
3
4
5
6
7
Figure 2-10: J15 (COM 1) and J16 (COM 2) Pin Designations
IND310drive Signal
Description J16
TxD2 RS-232C
RxD2 RS-232C
Ground
TXD+ (RS485/422)
TXD– (RS485/422)
RXD+ (RS485/422)
RXD– (RS485/422)
J 15 Pin 1
J16, Pin 1