Campbell Scientific CR7 Measurement and Control System - Manual (Page 151)

15-1
15. I/O CARD ADDRESSING AND MULTIPLE I/O MODULES
15.1 I/O CARD IDENTIFICATION
NUMBER DECODING
Each I/O card must be assigned a unique card
identification number and have jumpers set for
that number. The numbers allow the cards to
decode signals addressed to them by the I/O
Module. CR7s leave the factory with card
numbers assigned. These numbers may be
reassigned by the user when a CR7 needs to
be expanded with additional cards or
reconfigured for a particular application.
15.1.1 ASSIGNING CARD IDENTIFICATION
NUMBERS
Cards fall into one of two Categories. Category
1 includes all Excitation and Pulse Counter
cards; Category 2 includes Analog Input cards
only. NUMBERS MUST NOT BE
DUPLICATED WITHIN A CATEGORY, but a
number assigned in one category may be
duplicated in the other category. While the
identification numbers do not need to follow
physical order of the cards, it simplifies wiring
sensors if the card ID numbers match the
physical order.
When assigning card numbers the user can
avoid confusion by following 4 steps:
1. Categorize the cards.
2. Assign a valid number to each card.
3. Set the jumpers on the cards according to
the numbers assigned.
4. Insert the cards into the Control Module,
making certain that the correct number tag
is secured with each card (Figure 10.1-1).
Tables 15.1-2 and 15.1-3 list card numbers and
the corresponding jumper placement. The bus
structure allows one CR7 Control Module to
address up to 16 Excitation cards, 16 Pulse
Counter cards and 32 Analog Input cards. One
Control Module can control up to 4 I/O Modules.
15.1.2 PLACING JUMPERS IN THEIR PROPER
LOCATIONS
Jumpers are blue rectangular plastic and metal
sleeves, approximately 0.2" in length, with two
holes which are slipped over pins on the circuit
board.
Category 1 cards have 2 jumpers and Category
2 cards have 3 jumpers. Jumper positions are
labeled on the card. Figure 15.1-1 shows the
location of the jumpers on the Excitation, Pulse
Counter and Analog Input cards. Jumper
settings are listed in Tables 15.1-2 and 15.1-3.
TABLE 15.1-1. Jumper Locations and Labels
Card Jmp/ Card No.
Type Cat. Card Loc. Pins
Excitation 1 2 R2 6
R6 6
Pulse Count 1 2 R36 6
T32 6
Analog Input 2 3 R3 3
R4 6
R8 6