ABB AC 31 - 4.1.2. Transmission;reception range of a slave central unit; 4.1.3. Data initialization and backup

Programming
ABB Control - AC 31 Page 5-11
1SBC 260400 R1001-b 06.99
4.1.2. Transmission/reception range of a slave central unit
These parameters only act on the 50 series central units if it is configured as a slave.
The exchange of information between master and slave central units is not only limited to the
exchange of the physical input/output variables. It is in fact possible to exchange a data table:
- On transmission and on reception
- Binary (bits) or analog (words)
- With the size defined, on the slave central unit, in the "CS 31 bus communication:
transmitting and receiving area" configuration parameters
The size of the transmission table (x) may differ from the size of the reception table (y):
- The exchange of bits is effectuated by packets of 8 bits from 2 x 8 bits up to 15 x 8 bits.
- The exchange of words is comprised of between 1 and 8 words.
However, the reception data types (bits or words) should be the same as the transmission data
type:
Transmission data types Reception data types
Default values 32 bits 32 bits
It is possible to have: x bits y bits
x words y words
It is not permitted to have x bits y words
x words y bits
A change in these parameters is taken into account immediately.
4.1.3. Data initialization and backup
The variables are all initialized by default at each program launch.
It is, however, possible to save the totality or a part of the data on the 50 series central units.
An external battery is not necessary as the 50 series central units possess an incorporated
battery (accumulator Vanadium-lithium), which enables saving the data, with an autonomy of
20 days at 25°C, the battery recharges 0 up to 100% in 12 hours when the power supply is on.
A battery failure is detected with the bit 3 of the status word IW 62.15. If the value of IW 62.15
is such that the bit 3 is set to 0 (xxxx xxxx xxxx 0xxx) when the battery is failed.
The life time depends on the use of the CPU.
A normal case:
- the power supply is OFF every night life time = 15 years
- the power supply is OFF every week-end and day-off life time = 12 years
- the worst case power supply is every week for 4 days life time = 6 years
Data backup is possible by modifying the n value of the following tables.
The 40 series does not have a battery incorporated and doesn't allow data backups.