Pick unmanaged for a small, fixed network with one uplink and no remote monitoring. Pick managed once you need VLAN segmentation, ring redundancy, SNMP diagnostics, or a switch a colleague can configure remotely. Moxa builds both, and the EDS-208A against the EDS-408A makes the difference concrete.
Buyers often compare on port count and price, then discover later that the cheap switch cannot do the one thing the plant actually needed. The four sections below work through the questions in the order they usually decide the answer: how big the network is, whether it has to survive a broken cable, who has to diagnose it, and what the whole thing costs once engineering time is counted. The comparison table and the buying notes follow.
Four questions, in this order
- Network size. How many devices, how many switches, and is the network one cabinet or several cells?
- Redundancy. What happens to production when a cable or a switch fails?
- Diagnostics. Who finds the fault, how fast, and from where?
- Cost. Purchase price plus configuration, documentation and spare-part effort.
1. Network size
An unmanaged switch forwards frames and does nothing else. It has no IP address of its own, nothing to configure, no firmware to update, and no way for anyone to reach it. In a cabinet with eight devices and a single uplink to the control room, that is exactly the right behaviour. The EDS-208A series is that switch: eight 10/100BaseT(X) ports, optional 100BaseFX fibre in multi-mode or single-mode with SC or ST connectors, and a DIP switch for broadcast storm protection.
The picture changes as soon as the network is more than one segment. Two switches in a line, four cells on a common backbone, or one plant network shared by production and the office, and you need segmentation. A managed switch gives you IEEE 802.1Q VLANs and port-based VLANs, up to 64 VLANs with a VID range of 1 to 4094 on the EDS-408A, so machine traffic can be isolated from camera traffic without running separate cabling. Above roughly a dozen nodes, or anywhere the network map has to be explained on a drawing, the managed platform usually pays for itself the first time something has to be moved.
Port speed is a separate question from management. Unmanaged and managed switches are both available with fast Ethernet and Gigabit ports, and a Gigabit unmanaged switch is often better value than a fast Ethernet managed one on a small, high-bandwidth link.
2. Redundancy
This is the question that removes unmanaged switches from consideration altogether. Unmanaged switches have no spanning-tree and no ring protocol, so a second cable between two switches creates a loop and a broadcast storm. If production cannot tolerate a broken link, the answer is a managed switch.
The EDS-408A series supports Turbo Ring and Turbo Chain with a recovery time of under 20 ms at 250 switches, together with standard RSTP and STP where you have to interoperate with third-party equipment. Turbo Ring can be set up from the web interface, or from DIP switches on the panel, which matters on a machine that has to be back online in minutes rather than hours.
Redundancy also applies to power. Both the EDS-208A and the EDS-408A take redundant dual 12/24/48 VDC inputs over a 9.6 to 60 VDC range, and both provide a relay alarm contact for power failure and port break. On the managed model that alarm can also be sent as an email or a Syslog message, so the control room hears about it before the operator does.
3. Diagnostics
An unmanaged switch tells you almost nothing. Link and activity LEDs, and that is the whole story. When a machine drops off the network, someone walks to the cabinet and starts unplugging cables to find out where the break is.
A managed switch is a diagnostic instrument. The EDS-408A offers SNMPv1/v2c/v3 and RMON for monitoring, LLDP for neighbour discovery, Syslog and SMTP for alarms, port mirroring for capturing traffic during a fault, and per-port statistics that answer the useful question — is this port dropping frames, or is the device behind it dead? DHCP Option 66/67/82 covers address assignment policy, and the console port, Telnet, web interface, Windows utility and ABC-01 backup configurator give you more than one way in when the usual one is unavailable.
Put bluntly, the diagnostics are what you are buying. A fault that takes two hours of cable swapping on an unmanaged switch costs more than the price difference on the day it happens.
4. Cost
Unmanaged switches cost less to buy and less to own. Managed switches cost more upfront, and they add work: an address, a configuration, a password policy, a backup file, and someone who understands them.
Two things balance that. First, managed Moxa switches are configurable in the field through a web browser, so the engineering effort is a one-off rather than an ongoing cost. The ABC-01 backup configurator exists precisely so that replacing a failed switch does not mean rebuilding the configuration from memory. Second, security features such as HTTPS/SSL, SSH, SNMPv3, port lock and trust access control live only on the managed side. Where the plant network touches anything outside the plant, that matters.
The usual compromise is a mixed network: one managed switch where the segments meet, unmanaged switches at the edges where nothing is configured and nothing changes. That gives you segmentation, ring redundancy and remote diagnostics in the one place they pay, without paying for management on every panel.
EDS-208A against EDS-408A
Both are Moxa, both are 8-port class, and both are built for the same cabinets. The difference is entirely in the firmware.
| EDS-208A (unmanaged) | EDS-408A (managed) | |
|---|---|---|
| Ports | 8 × 10/100BaseT(X) RJ45; fibre models offer 100BaseFX (SC or ST) | 8 × 10/100BaseT(X) RJ45 on base models; fibre variants use 6 or 5 RJ45 plus 2 or 3 fibre ports |
| VLAN | Not supported | IEEE 802.1Q and port-based, up to 64 VLANs, VID 1 to 4094 |
| Redundancy | None | Turbo Ring and Turbo Chain (recovery under 20 ms at 250 switches), RSTP, STP |
| Diagnostics | Link and activity LEDs only | SNMPv1/v2c/v3, RMON, LLDP, Syslog, SMTP alerts, port mirroring |
| Remote configuration | None | Web, CLI, Telnet, serial console, Windows utility, ABC-01 |
| Multicast and QoS | None | IGMP snooping, QoS (IEEE 802.1p, TOS/DiffServ), four priority queues |
| Industrial protocols | Transparent pass-through | EtherNet/IP, Modbus TCP, PROFINET IO on PN models |
| Security | None | HTTPS/SSL, SSH, SNMPv3, port lock, trust access control |
| Power | Redundant dual 12/24/48 VDC (9.6 to 60 VDC), relay alarm | Same |
| Housing | IP30 aluminium, DIN-rail | IP30 metal, DIN-rail or wall |
| Temperature | -10 to 60 °C, or -40 to 75 °C on -T models | Same |
| Console port | None | RS-232 (RJ45) |
What to buy for which network
- A single cabinet, under about eight devices, one uplink, nothing to monitor: EDS-208A unmanaged. Add a fibre model if the run to the control room is long or electrically noisy.
- Continuous process where a broken link halts production: EDS-408A managed, configured as a Turbo Ring or Turbo Chain. There is no unmanaged equivalent of this.
- Multicast on the wire — vision cameras, PROFINET or EtherNet/IP I/O: managed, because IGMP snooping and QoS are what keep that traffic from flooding every port.
- Several cells sharing one backbone, or an OT network that touches the business network: managed for VLANs and for the access-control features.
- Remote site with no regular IT presence: managed, so faults arrive as email or Syslog rather than as a phone call.
- A brownfield panel where the switch is a dumb conduit and nobody will ever log in: unmanaged, and put the saving into the uplink or the enclosure.
- Mixed estate: one managed core switch, unmanaged edges. That is the pattern that keeps both the budget and the diagnosis sane.
Send us the network, not the part number
If you know the switch you want, a photograph of the label and the quantity is enough. If you are still deciding, four facts let us specify it in one pass: how many devices per switch, whether the link between switches has to survive a cable break, whether anything has to be monitored remotely, and the supply voltage available in the cabinet. From those we can name the model, confirm the port and fibre mix, and check availability.
- Browse the Moxa range we carry, including the EDS switch families.
- Compare the safety and control products that share the same cabinets.
- Read more selection and cross-reference guides in the Insights library.
- Send the network details straight to the inquiry form.
Every switch we supply is original and new, bought through the manufacturer or established distribution channels, with procurement documentation for verification on arrival.