Micromod Micro-DCI: 53MC5000 Multi-Loop Process Controller Instruction Manual - Manual (Page 340)

APPENDIX B.0 COMMUNICATIONS
B.1 STANDARD COMMUNICATIONS
Two digital communication channels are provided with the controller: 1) There is a configuration
port that is an RS-232 serial interface. It is accessed via a 5 pin mini-DIN connector located under
the pull-down door on the front panel. It is used to configure controller parameters for selected op-
erational characteristics. The parameters are configured with the Hand Held Configurer (HHC) as
described in Section 3, or with a customer supplied personal computer executing the appropriate
software. 2) There is also an RS-422/485 serial interface used to connect the controller to a
Datalink multi-drop network. Interface connection to the Datalink network is via the rear terminal
board (TB1) of the controller, pins 19 through 22, as shown in Section 2, Installation.
Information in this section applies to both the configuration port and the Datalink interface, with the
following exceptions:
1. The configuration port data rate is 9600 baud, with 8 data bits, and no parity.
2. The configuration port powers up in standard mode suitable for use with the HHC, but
can be switched to binary mode by sending the following four character sequence:
Sent 03
H 1B H 0E H 15 H
Echoed 0D
H
0A
H
1B
H
20
H
0E
H
20
H
15
H
Note: Numbers used in this section that are expressed in hexadecimal notation
(base 16) are identified with a subscript
H
after the number .
After echoing the 15 H character, the controller switches to binary mode and is able to
process binary communications messages from that time on. (Characters sent after the
15
H
and before the 15
H
echo are ignored.)
3. Once the configuration port switches to binary mode, it remains in that mode as long as
the connection is maintained. The connection is maintained by sending a character at
least once every 30 seconds. If 30 seconds elapses without a character being received
by the controller through the configuration port, the port returns to standard mode.
4. When in binary mode, the configuration port responds to all messages regardless of the
address to which they are directed.
The Datalink interface requires four conductors: a transmit pair and a receive pair. The voltage lev-
els of each conductor pair conform to the EIA RS-422/485 standard. In accordance with this stand-
ard, the overall Datalink network distance is limited to 4000 feet when #24 AWG twisted pair wire is
used to interconnect the nodes. Adapters are available to convert RS-422/485 to RS-232 or 20 mA
current loops.
In a Datalink network, the controllers communicate as Responders to host or SUPERVISOR-PC
queries. The host or personal computer functions as the Interrogator and acts as the central con-
trol point for the Datalink network. A maximum of 32 addressable controllers can be connected to
a Datalink network. Using the SUPERVISOR-PC in a Datalink network system allows a variety of
services to be implemented as described in the SUPERVISOR-PC Instruction Bulletin, 53SU5000.
Appendix B. Communications
B-1