Understanding the Series 90-30 Platform
What is the typical 90-30 rack architecture?
A standard system uses a power supply in the leftmost position, a CPU in Slot 1, and I/O/option modules in the remaining slots. You can add expansion/remote baseplates via the right-side expansion port; only one CPU baseplate exists per system.
Which CPUs are common and how do they differ?
Embedded base CPUs (e.g., IC693CPU311/313) are compact for small machines; rack CPUs (e.g., IC693CPU350/364/374) add performance, memory, and options like onboard Ethernet (364/374). Choose by scan time, memory, ports, and Ethernet needs.
Programming tools & project migration
Use Proficy Machine Edition (Logic Developer – PLC). Legacy Logicmaster 90 projects can typically be imported into Proficy for modernization and ongoing support.
Selection Tips & Compatibility Notes
How do I size the power supply for a 90-30 rack?
Sum each module’s +5 V backplane current plus any consumption from the 24 V isolated/relay rails. Pick a supply (e.g., IC693PWR321/322/330) with headroom for inrush and future modules.
Baseplates, slots, and mechanical rules
PSU leftmost, CPU Slot 1, remaining slots for I/O/option cards. Use 5-slot (e.g., CHS397) or 10-slot (CHS391) baseplates per space/point needs, and install filler modules in unused slots to protect the backplane.
Networking, Integration & Lifecycle
Adding Ethernet to an existing rack
Use a CMM321 Ethernet Interface (SRTP, some revs support Modbus/TCP) or upgrade to an Ethernet CPU such as IC693CPU364/374. Initial IP setup is via the Station Manager serial port before switching to Ethernet.
Fieldbus options for third-party devices
90-30 supports multiple fieldbuses via option modules—DeviceNet Master (IC693DNM200), PROFIBUS-DP Master (IC693PBM200), plus serial comms (CMM311, SNP/CCM/Modbus RTU slave). Check slot placement and backplane load when adding networks.
Lifecycle & phased modernization
Many sites keep 90-30 running with like-for-like spares while planning staged upgrades. Typical path: retain baseplates/I/O, add Ethernet or gateways, then migrate CPU logic with minimal rewiring. Keep firmware notes, batteries, and spare PSUs/CPUs on hand to reduce downtime.