7
1.3.3 Installation and replacement of modules
Before the instrument delivery, module installation is done on request, with corresponding
parameter set correctly.
Users can replace or install modules by themselves when needed. When replacing a module, you
should pull the controller out of the housing at first, insert a small flat-tip screwdriver into the
opening between the original module and the slot on motherboard to remove the old module, and
then install a new module. Changing module type needs to modify the corresponding parameters.
1.3.4 Electric isolation of the modules
There are a group of 24V and a group 12V power supply built in the instrument and isolated to the
main circuit. The 24V power commonly supplies voltage output module, such as V24/V12/V10/V5,
I2 and I4. The 12V power is commonly supplies output or communication module. Generally, the
relay contact output and TRIAC no contact discrete output are self insulated from the other circuit,
no matter whether other modules are installed or not. SSR output voltage does not need to be
insulated from input circuit, because SSR itself has isolation function. Therefore, only the electric
isolation between the communication interface and the current output should be considered. Those
modules, for example, S (RS485 communication interface), R (RS232 communication interface)
and X3 (linear current output), all need the 12V power supply. If more than one of the above
modules are installed, in order to be electric isolated, only one of them can be module without
electric isolation, the other modules should be S4 or X5, which has its own isolated power supply.
For example, if an X3 module is installed in OUTP (main output) slot, for isolate purpose,
COMM slot should be install S4 or X5.
1.3.5 Further descriptions about module applications
Voltage output module:
The voltage output modules like V24, V12, \/10 or V5 are often used
for supplying power for external transducer or feedback resistance of transmitter. These modules
can be installed in any slot. To standardize the wiring, it is recommended to be installed in the first
idle slot in the order of MIO, AUX,and COMM.
No contact switch module:
W1 and W2 are new types of no contact switch module which
apply the advanced technology of
“
burn proof
”
and zero crossing conduction. It can replace the
relay contact switch. Compared to the relay contact output module, W1 and W2 have longer life
and lower interference. They can be largely lower the interference spark of the equipment, and
greatly improve the stability and reliability of the system. Protection elements are series wound to
the output terminals, so it can control continuous current up to 0.2A with maximum allowed
instantaneous current 2A. Since the driver element is TRIAC, it is suitable for controlling
100-240VAC (not for DC power) with contactor which current below 80A. For the current larger than
80A, an intermediate relay is needed.
