![background image](http://html1.mh-extra.com/html/racal-instruments/1260-x121/1260-x121_user-manual_3140572028.webp)
1260-X121 User Manual
Module Operation 3-6
Racal Instruments
©
2005
Table 3-6, Register3 Functionality of the 1260-X121 Module
Register Table
Register 3
Module Version
Bit
Functionality Description
0
Relay 24 (Connect J200-P and J200-X)
(0: relay open
1: relay closed)
1
Relay 25 (Connect J201-C and J201-B)
(0: relay open
1: relay closed)
2
Relay 26 (Connect J201-A and J201-K)
(0: relay open
1: relay closed)
3
Relay 27 (Connect J201-J and J201-H)
(0: relay open
1: relay closed)
4
Relay 28 (Connect J201-S and J201-R)
(0: relay open
1: relay closed)
5
Relay 29 (Connect J201-P and J201-X)
(0: relay open
1: relay closed)
6
Not Used
All
7
Not Used
Note:
Open:
Indicates C not connected to NO contact
Closed:
Indicates C connected to NO contact
Table 3-7, EPROM Descriptor Functionality of the 1260-X121 Module
Register Table
EPROM Descriptor Register
Module Version
Bit
Functionality Description
0
1
2
3
4
5
6
All
7
Each time this register is read, it advances a memory pointer to
the next memory location in the on-board EPROM. To reset this
pointer to the beginning, read the ID register. This resets the
memory pointer. The descriptor register contains a long string of
data, typically used by the Adapt-a-Switch carrier for configuration
purposes. Additionally, this data contains the card identification
string for the specific type of card (i.e. 1260-121). These
identification strings are located at EPROM memory locations
0x23 through 0x34.
Writing to a port location is a straightforward process. Setting a bit
high in a port register causes the corresponding relay channel to
close.
It is especially important to realize that a single write operation
controls eight separate control lines or output devices
simultaneously. Therefore if only a single bit change is desired,
the following process must be observed.