Active Current Loop Interface - Mettler Toledo IND500x Installationsanleitung

Figure 39: Sample RS-232 Connection
A barrier that has been tested for correct operation with the IND500x, and can be connected directly to COM6,
is:
MTL7761Pac (FM and ATEX approvals)
2.5.6 I.S. Active Current Loop Interface
There is an optional intrinsically safe active current loop interface board that provides communication to an
ACM200 or ACM500 in a safe area, or an IND256x terminal (or similar, see Control Drawing #30595335) as
a remote display inside the hazardous area. This option can be ordered already installed into the terminal at the
factory or is available as a kit that can be installed in the field. Instructions are included with the kit showing the
installation procedure of the option into the terminal as shown in the following figure.
Figure 40: I.S. Active Current Loop Interface (left), installed (right)
The interface board provides two circuits for communication to the ACM500 or a single channel to the ACM200
or the IND256x terminal (or similar, see Control Drawing #30595335). If connecting to an ACM500,
depending upon the options used in the ACM500, it may not be necessary to provide connections to both
circuits. Refer to the table below to determine if both the COM4 and the COM5 circuit must be connected.
Interface Port Wiring
Option Used in ACM500
COM2 Port
COM3 Port
Ethernet TCP/IP
PLC Option
Each I.S. CL interface cable used must contain two twisted pair conductors, and each conductor must be a
minimum of 0.5mm
connection cables are available in various sizes from METTLER TOLEDO. Please see the appropriate price
pages and catalogs for available sizes and part numbers.
IND500x
Ex Area
Barrier
COM4 Required
Yes
Yes
--
Yes
2
(20 GA or 0.032 AWG) in size. A separate cable is required for each COM port used. CL
Safe Area
RS232 Device
COM5 Required
--
--
Yes
--
Installation​ ​ 37