Download 1760 manual - Advanced Micro Controls Inc

4
MODULE ADDRESSING
Addressing Examples (continued)
1-Slot Addressing
I/O Group
Number
Rack Number: 01
I/O Group Numbers: 0,1
Module Slot Number: 0
I/O Rack Number 0
0 1
2 3
0
0 0
4 5
6 7
I/O Rack Number 1
0 1
2 3
4 5
6 7
0
0 0
BT Address: 0110
ST Upper Position Addr: I:010
ST Lower Position Addr: I:011
0
0 0 0 0 0 0 0
Module Slot Numbers
0
0
Figure 4.3 2-Slot Address Example
1/2-Slot Addressing
I/O Group
Number
Rack Number: 02
I/O Group Numbers: 2,3
Module Slot Number: 0
I/O Rack 0
I/O Rack 1
I/O Rack 2
I/O Rack 3
0,1 2,3 4,5 6,7 0,1 2,3 4,5 6,7 0,1 2,3 4,5 6,7 0,1 2,3 4,5 6,7
BT Address: 0220
ST Upper Position Addr: I:022
ST Lower Position Addr: I:023
0
0
0 0
0 0 0 0 0 0 0
Module Slot Numbers
0
0
0
0 0
Figure 4.4 ½-Slot Address Example
Restrictions and Warnings
h The 1761 or 1762 module must be installed in a single slot pair in order to operate properly. See
h
h
h
h
Installing the Module on page 31 for more information on installing a module.
The A-B backplane interface IC was designed primarily as a block transfer controller. Because of this,
32 bit single transfers with 1-slot addressing do not work with all processors. It is the users responsibility to test 32 bit single transfers in the system to determine if transfer operates correctly.
When using a 1761 or 1762 module in a Remote I/O chassis, the I/O Adapter must be a 1771 - ASB,
Series B, Firmware Rev. F, or later. A Remote I/O Adapter that has an earlier Series or Firmware Revision may not work properly with the module.
If you change the Transfer Type or PLC Program parameters, you must cycle power to the module to reinitialize the A-B backplane interface IC.
If your system presently uses a 1761 as a block transfer module and you are converting the module to a
single transfer module, remember to remove all block transfer instructions that access the module.
Block transfers use the I/O group bits for block transfer control. Therefore, block transfers can corrupt
single transfer data.
Do configure the 1761 module to use single transfers when installing the module in a
remote rack. Under some conditions, it is possible that the 32 bit data from the 1761
will be corrupted when it is read by the Remote I/O Adapter. This occurs due to limited
handshaking between a Remote I/O Adapter and the 1761 which can result in the
Remote I/O Adapter reading the 1761’s data while the module is updating it. This form
of data corruption cannot occur when the 1761 is in a local rack.
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ADVANCED MICRO CONTROLS INC.