Micromod Micro-DCI: 53IT5100B Micro-DCI 4-Channel Indicator Totalizer - Manual (Page 57)

53IT5100B Indicator/Totalizer
INSTRUCTION MANUAL
53
Appendix B : Communications
Two digital communication channels are provided with this instrument:
 RS-232 serial configuration port, accessed via a 5 pin mini-DIN connector located under the pull-
down door on the front panel (see Figure 1-2). It is used to configure instrument parameters for
selected operational characteristics. The parameters are configured with Micro-Tools software
running on a customer supplied PC.
 RS-422/485 serial interface used to connect the instrument to a Datalink multi-drop network. Interface
connection to the Datalink network is via the rear terminal board (TB1) of the instrument, pins 19
through 22, as shown in Section 2.
Information in this section applies to both the configuration port and the Datalink interface
The configuration port data rate is 9600 baud, with 8 data bits, and no parity.
The Datalink interface requires four conductors: a transmit pair and a receive pair. The voltage levels of each
conductor pair conform to the EIA RS-422/485 standard. In accordance with this standard, 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 instruments communicate as Responders to host queries. The host or PC functions
as the Interrogator and acts as the central control point for the Datalink network. A maximum of 32
addressable instruments can be connected to a Datalink network.