Rockwell Automation MHB44IND Pulse Input and Analogue Output Module - Manual (Page 6)

6 MHB44IND October 2005 – Issue 2
Triguard SC300E
TECHNICAL DESCRIPTION
PHYSICAL
The MHB44IND is a 9U high PCB with integral front panel and rear connectors. A plug-in
daughterboard carries the common interface circuits. Figure 1-1 shows the general layout,
including the location of the connectors, covers and configuration links.
The front panel provides the following: Three ‘On-Line’ indicators A ‘Health’ indicator
An On/Off line request switch
Eight test jacks as monitor points for the pulse input lines
Four received-pulse indicators (one per input pair)
Four test jacks (plus common) for monitoring the output lines.
NOTE
Each monitor point gives 0 to 5.5Vdc negative with respect to common, determining the current
flowing in the corresponding 0 to 22 mA output. Each monitor point has a 10k ohm resistance
in series to prevent malfunction if the monitor point is short circuited - so a high input-
resistance meter is required for accurate readings.
MECHANICAL CODING BLOCKS
All Input/Output modules carry two mechanical coding blocks equipped with pins which mate
with holes in corresponding blocks in the chassis and prevent the module being inserted into
the wrong slot. The pins in the module blocks are factory installed in a pattern determined by
the module and corresponding set screws are removed from the chassis coding blocks to
enable fitting. Unused holes are plugged with set screws. The chassis mechanical coding
block configuration for this module is shown in Figure 2-1 .
Figure 2-1 Chassis mechanical coding block configurations