ABB AC500 PLC Hardware Manual page 1221

If a Processor Module provides more than one serial interface, both interfaces (COM1/COM2)
can be operated simultaneously as Modbus interfaces and can operate as Modbus server as
well as Modbus client.
Bus topology Point-to-point with RS-232 or bus topology with RS-485. Modbus is a master-slave protocol.
For further information on Modbus see chapter Communication with Modbus RTU.
2.5.5 Handling of Accessories
This section only describes accessories that are frequently used for system assembly, connec-
tion and construction. A description of all additional accessories that can be used to supplement
AC500 system can be found in the Hardware PLC device description.
2.5.5.1 MC502 - SD Memory Card
● Secure digital card
● Solid state flash memory storage
Purpose The SD memory card is used to back-up user data and store user programs or project source
codes as well as to update the internal CPU firmware. The processor modules can be operated
with and without SD memory card.
AC500/AC500-eCo processor modules are supplied without SD memory card. It therefore must
be ordered separately.
The MC memory card can be read on a PC with a standard memory card reader. AC500 pro-
cessor modules are equipped with an MC memory card reader.
For AC500-eCo processor modules the device must be equipped with a MC503 SD memory
card adaptor
2019/04/17
Ä Chapter 2.5.5.2 "MC503 - SD Memory Card Adaptor" on page 1223.
The SD memory card has a write protect switch. In the position "LOCK", the
card can only be read.
The use of memory cards other than the MC502 SD memory card is prohibited.
ABB is not responsible nor liable for consequences resulting from use of unap-
proved memory cards.
3ADR010121, 13, en_US
System Assembly, Construction and Connection
AC500-eCo > Handling of Accessories
1221