PoE SwitchesHPE Networking
- 4× 2.5G Class 6
- 370 W budget
- 140 Gbps
HPE Networking · PoE Switches
S4A31A – HPE Networking Instant On Switch 24p Gigabit CL4 PoE 4p SFP+ 240W 1940
Twenty-four port rack switch with Class 4 PoE on every port, a 240 W budget and four 1/10G SFP+ uplinks.
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- PoE ports
- 24× GbE Class 4 PoE (ports 1–24)
- Uplinks
- 4× 1/10G SFP+ (ports 25–28)
- PoE budget
- 240 W
- Per-port PoE
- Up to 30 W (Class 4)
- Switching capacity
- 128 Gbps
- Mounting
- 1U rack, 2-post kit included
- Ready Stock
- PAN India Supply
- Same Day Dispatch*
- GST Billing
- BOQ Assistance
*Same-day dispatch applies to in-stock items ordered before cut-off from the Delhi NCR warehouse.
Key Features
What the S4A31A is built to do
Technical Specifications
S4A31A specifications
Specifications as published for this model. Confirm project-critical values against the datasheet before ordering.
| Ports | |
|---|---|
| PoE ports | 24× RJ-45 autosensing 10/100/1000BASE-T with IEEE 802.3af/at Class 4 PoE (ports 1–24) |
| Uplink | 4× SFP+ 1/10GbE ports (ports 25–28) |
| Standards | IEEE 802.3 Type 10BASE-T, IEEE 802.3u Type 100BASE-TX, IEEE 802.3ab Type 1000BASE-T |
| Duplex | 10BASE-T/100BASE-TX: half or full; 1000BASE-T: full only |
| Console port | 1× USB-C console port |
| PoE | |
|---|---|
| Total PoE budget | 240 W Class 4 PoE |
| PoE port count | 24 of 24 access ports |
| Per-port maximum | Up to 30 W (IEEE 802.3at) |
| Standards | IEEE 802.3af / 802.3at |
| Scheduling | PoE scheduling via global schedules (up to 3) |
| Performance | |
|---|---|
| Switching capacity | 128 Gbps |
| Throughput | 95 Mpps @ 64-byte packets |
| Latency (100 Mb, LIFO) | < 6.5 µs |
| Latency (1000 Mb, LIFO) | < 2.7 µs |
| Latency (10000 Mb, LIFO) | < 0.75 µs |
| MTBF | 102 years |
| Scale | |
|---|---|
| MAC address table | 16,000 entries |
| Maximum VLANs | 256 (VLAN IDs 1–4093) |
| IPv4 host table (ARP) | 509 entries |
| IPv4 unicast static routes | 32 |
| Routing table | 32 IPv4 static entries |
| IGMP groups | 1K |
| IPv4/MAC ACL entries (ingress) | 100 |
| Maximum ACEs | 2048 |
| Jumbo frames | Up to 9216 bytes |
| IPv4/MAC ACL entries (egress) | 512 |
| Link aggregation groups | 16 (4 members per group) |
| Processor and Memory | |
|---|---|
| Processor | ARM Cortex-A9 @ 1.25 GHz |
| SDRAM | 1 GB |
| Flash | 512 MB |
| Packet buffer | 2 MB |
| Physical | |
|---|---|
| Dimensions (D × W × H) | 12.09 × 17.48 × 1.73 in (30.70 × 44.40 × 4.40 cm) |
| Weight | 8.02 lb (3.64 kg) |
| Fans | 2 fixed fans, non field-replaceable |
| Primary airflow | Left to right |
| Acoustics | Sound power LWAd = 3.5 Bel; bystander sound pressure LpAm = 20 dB |
| Mounting | EIA-standard 19 in. rack or cabinet (2-post kit included); table-top; rack; wall; under-table |
| Electrical | |
|---|---|
| Power supply type | Internal power supply |
| AC voltage | 100–127 VAC / 200–240 VAC |
| Frequency | 50 Hz / 60 Hz |
| Current | 3.00 / 1.52 A |
| Power consumption (100% traffic) | 100–127 V: 35.1 W; 200–220 V: 34.7 W |
| Power consumption (100% traffic + 100% PoE) | 100–127 V: 304.7 W; 200–220 V: 299.4 W |
| Power consumption (idle) | 100–127 V: 18.0 W; 200–220 V: 17.4 W |
| Heat dissipation (100% traffic + 100% PoE) | 100–127 V: 1039.6 BTU/hr, 1096.8 kJ/hr; 200–220 V: 1021.7 BTU/hr, 1078.0 kJ/hr |
| Environment | |
|---|---|
| Operating temperature | 32 °F to 104 °F (0 °C to 40 °C) |
| Storage temperature | −40 °F to 158 °F (−40 °C to 70 °C) |
| Operating humidity | 15% to 95% @ 104 °F (40 °C), non-condensing |
| Storage humidity | 15% to 95% @ 140 °F (60 °C), non-condensing |
| Altitude | Up to 10,000 ft (3 km) |
| Layer 2 Switching | |
|---|---|
| Spanning tree | 802.1D STP, 802.1w RSTP, 802.1s MSTP (local web only, up to 8 instances), BPDU filtering, loop protection |
| Flow control | IEEE 802.3x, symmetric and asymmetric |
| Link aggregation | LACP or static, up to 16 LAGs with up to 8 ports each depending on model |
| Multicast | IGMP v1, v2, v3 snooping |
| Discovery | LLDP and LLDP-MED |
| Monitoring | Port mirroring and RSPAN |
| Auto VLAN | Auto-detects access points and cameras into pre-defined VLANs |
| Auto recovery | Returns a port or service online after an error condition |
| Layer 3 Routing | |
|---|---|
| Static IPv4 routing | Up to 32 IPv4 routing interfaces and 32 IPv4 static routes |
| Address assignment | Manual or DHCP, per port or per VLAN |
| ARP | Dynamic and manual entries |
| IPv6 | IPv6 Host mode |
| Quality of Service | |
|---|---|
| Classification | CoS by IEEE 802.1p or DSCP; Global Trust Mode |
| Queue scheduling | Weighted round robin (WRR) or strict priority (SP) |
| Traffic shaping | Per-port egress bandwidth limit |
| Rate limiting | Broadcast, multicast and unicast thresholds with port shutdown or SNMP trap |
| Auto-voice VLAN | Detects SIP, H.323 and SCCP or by OUI |
| Security | |
|---|---|
| Hardware root of trust | TPM 2.0 |
| Port authentication | IEEE 802.1X |
| AAA | RADIUS, TACACS+ or local database |
| RADIUS servers | Up to 2, with RADIUS-assigned dynamic VLANs and accounting |
| DoS protection | Automatic denial-of-service protection |
| Access control | ACLs with MAC and IP filtering; time-based ACLs |
| Management | |
|---|---|
| Options | Instant On Cloud Portal; Mobile App; Web Browser; SNMP Manager; DOCs (Telnet, SSH); Console Port (USB-C) |
| Local web sessions | Up to 5 HTTP / HTTPS |
| Devices per site | Up to 125 |
| Scheduling | Up to 3 global schedules for ACLs, port shutdown or PoE |
| Diagnostics | Event logging and alerts, locator LED, port mirroring |
| Supported Transceivers (1G SFP) | |
|---|---|
| S0G20A | Instant On 1G LX SFP LC 10 km SMF transceiver |
| R9D16A | Instant On 1G SFP LC SX 500 m OM2 MMF transceiver |
| R9D17A / R9D17B | Instant On 1G SFP RJ45 100 m Cat5e transceiver |
| Supported Transceivers (10G SFP+) | |
|---|---|
| S0G21A | Instant On 10G LR SFP+ LC 10 km SMF transceiver |
| S0G18A | Instant On 10GBASE-T RJ45 30 m Cat6a transceiver |
| R9D18A | Instant On 10G SFP+ LC SR 300 m OM3 MMF transceiver |
| R9D19A / R9D20A | Instant On 10G SFP+ to SFP+ 1 m / 3 m direct attach copper cable |
| Compliance & Warranty | |
|---|---|
| Safety | EN/IEC 62368-1 2nd & 3rd Ed.; UL 62368-1 3rd Ed.; CAN/CSA C22.2 No. 62368-1 3rd Ed.; EN/IEC 60825-1:2014 Class 1 |
| Emissions | EN 55032:2015/CISPR 32 Class A; FCC CFR 47 Part 15:2018 Class A; ICES-003 Class A; VCCI-32 Class A; CNS 13438 Class A; KS C 9832 Class A; AS/NZS CISPR 32 Class A |
| Immunity | BS/EN 55035, CISPR 35, KS C 9835; IEC 61000-4-2/-3/-4/-5/-6/-8/-11 |
| Warranty | HPE Networking Instant On limited lifetime; chat support for the life of the product |
Specifications sourced from the official HPE Networking catalogue. Where official pages disagree on a value, it is marked and confirmed during quotation.
Overview
About the S4A31A
The HPE Networking Instant On Switch 24p Gigabit CL4 PoE 4p SFP+ 240W 1940 (S4A31A) is a 24-port smart-managed Layer 2+ gigabit switch in which every access port supplies IEEE 802.3af/at Class 4 PoE within a 240 W budget, plus four dedicated SFP+ uplinks at 1G or 10G.
PoE on all 24 ports rather than half is the practical difference from the 1840 generation at this size: there is no need to plan which drops land on powered ports, because every one of them is. The 240 W budget averages 10 W per port across a fully populated switch, which covers typical access points and fixed dome cameras.
Switching capacity is 128 Gbps with 95 Mpps forwarding, matching the non-PoE S4A30A, and two fixed fans handle the PoE stage at 3.5 Bel. At full traffic with full PoE it draws 304.7 W, which is the figure to size the rack circuit against.
Applications
Where the S4A31A is deployed
Downloads
S4A31A documents
Datasheets and manuals are shared without sign-up. Documents not yet hosted online are sent on request within working hours.
- HPE Networking Instant On Switch Series 1940 QuickSpecs (PDF)Download
Related Products
Pairs with the S4A31A
Edge PoE switches below it, SFP+ modules in its uplinks, and sibling models for smaller or larger sites.
- PoE Switches
Managed Switches- 24× GbE
- 4× 1/10G SFP+
- 128 Gbps
PoE Switches- 48× GbE PoE
- 370 W budget
- 4× SFP+
Before You Enquire
Frequently asked questions
How many ports on the S4A31A supply PoE?
All 24. Every access port supplies IEEE 802.3af/at Class 4 PoE at up to 30 W within a 240 W total budget, so there is no need to plan which drops land on powered ports.
S4A31A or S4A32A — which 24-port PoE model do I need?
The S4A31A gives 24 gigabit Class 4 PoE ports and 240 W. The S4A32A replaces four of those with 2.5G Smart Rate ports carrying Class 6 PoE at up to 60 W, and lifts the budget to 370 W. Choose the S4A32A where Wi-Fi 6E or Wi-Fi 7 access points need multi-gigabit uplinks and more than 30 W.
Compare the S4A32AWhat circuit does the S4A31A need at full load?
At 100% traffic with 100% PoE it draws 304.7 W at 100–127 V or 299.4 W at 200–220 V, with a rated current of 3.00 / 1.52 A and heat dissipation of 1039.6 BTU/hr.
Can PoE be switched off outside business hours?
Yes. Up to three global schedules can be configured and applied to PoE power delivery, port shutdown or time-based ACLs.
What is the price of the HPE S4A31A in India?
Pricing is quotation-based with dealer slabs for registered partners. Name the S4A31A and quantity in a quote request and you receive priced options with confirmed availability within 24 working hours.
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