Saia-Burgess Controls AG
Manual
Manual PCD 1 / PCD 2 Series
│ Document 26
/
737 E
N22 │ 2013-11-26
CPUs and expansion housings
3-19
Expansion housings and bus cables
3
3.6
Expansion housings and bus cables
The PCD2.M120/M150/M170/M480 can be expanded with PCD2, PCD3 or PCD4
components, and additional module sockets are provided:
Type
M120/M150
M170
M480
Maximum number of inputs/outputs or
I/O module sockets for the system:
When PCD2 components used exclusively
255
1)2)
16
When expanded with PCD3 components
255
1)2)
16
510
1)2)
32
1023
1)2)
64
When expanded with PCD4 components
255
2)3)
16
1) Using digital I/O modules PCD2/3.E16x or A46x with 16 I/Os each
2) On all PCD2s, address 255 is reserved for the watchdog; on the M170, address 511 is also reserved for this
purpose. The I/Os reserved for the watchdog cannot be used by the user, and no analogue or H modules may be
attached to sockets with base address 240 (and on the M170, 496 also)
3) Not all PCD4 I/O modules are suitable for use with PCD2 CPUs; please refer to the section on
“Expansion with
PCD4 components”
