Editing Serial port (section)

===Pinouts===
The following table lists commonly used RS-232 signals and pin assignments:<ref>{{cite web |url=http://www.hardwarebook.info/Serial_(PC_9) |title=Serial (PC 9) |author-first=Joakim |author-last=Ögren |access-date=2010-07-07 |archive-url=https://web.archive.org/web/20100811173526/http://www.hardwarebook.info/Serial_%28PC_9%29 |archive-date=2010-08-11 }}</ref>

{| class="wikitable sortable" style="margin:auto; text-align:center;"
! colspan="3"|Signal !! colspan="2"|Direction !! colspan="11"|Connector pin
|-
! rowspan="2"|Name !! rowspan="2"|[[ITU-T V.24|V.24]] circuit !! rowspan="2"|Abbreviation !! rowspan="2"|[[Data terminal equipment|DTE]] !! rowspan="2"|[[Data circuit-terminating equipment|DCE]] !! rowspan="2"|[[DB-25]] !! rowspan="2"|{{nowrap|[[DE-9]]}} {{nowrap|([[TIA-574]])}} !! rowspan="2"|[[Modified Modular Jack|MMJ]] !! colspan="5"|[[8P8C]] ("RJ45") !! colspan="3"|[[10P10C]] ("RJ50")
|-
! [[EIA/TIA-561]] !! Yost (DTE)<ref name="Yost">{{cite web |url=http://yost.com/computers/RJ45-serial/ |title=Yost Serial Device Wiring Standard |access-date=2020-05-10 |archive-url=https://web.archive.org/web/20200617132523/http://yost.com/computers/RJ45-serial/ |archive-date=2020-06-17 |url-status=dead }}</ref> !! Yost (DCE)<ref name="Yost"/> !! Cyclades !! [[Digi International|Digi]] (ALTPIN option) !! [[National Instruments]]<ref name="National Instruments 2013">{{cite web |url=http://www.ni.com/pdf/manuals/371253e.pdf |publisher=National Instruments |title=Serial Quick Reference Guide |website=NI.com |date=July 2013 |access-date=2021-06-18 }}</ref> !! Cyclades !! Digi
|-
| Transmitted Data || 103 || TxD
| Out || In || 2 || 3 || 2 || 6 || 6 || 3 || 3 || 4 || 8 || 4 || 5
|-
| Received Data || 104 || RxD
| In || Out || 3 || 2 || 5 || 5 || 3 || 6 || 6 || 5 || 9 || 7 || 6
|-
| Data Terminal Ready || 108/2 || DTR
| Out || In || 20 || 4 || 1 || 3 || 7 || 2 || 2 || 8 || 7 || 3 || 9
|-
| Data Carrier Detect || 109 || DCD
| In || Out || 8 || 1 || {{n/a}} || 2 || rowspan="2"|2 || 7 || 7 || 1 || 10 || 8 || 10
|-
| Data Set Ready || 107 || DSR
| In || Out || 6 || 6 || 6 || rowspan="2"|1 || {{n/a}} || 8 || {{n/a}} || 5 || 9 || 2
|-
| Ring Indicator || 125 || RI
| In || Out || 22 || 9 || {{n/a}} || {{n/a}} || {{n/a}} || {{n/a}} || {{n/a}} || 2 || 10 || 1
|-
| Request To Send || 105 || RTS
| Out || In || 4 || 7 || {{n/a}} || 8 || 8 || 1 || 1 || 2 || 4 || 2 || 3
|-
| Clear To Send || 106 || CTS
| In || Out || 5 || 8 || {{n/a}} || 7 || 1 || 8 || 5 || 7 || 3 || 6 || 8
|-
| Signal Ground || 102 || G
| colspan="2" | Common || 7 || 5 || 3, 4 || 4 || 4, 5 || 4, 5 || 4 || 6 || 6 || 5 || 7
|-
| Protective Ground || 101 || PG
| colspan="2" | Common || 1 || {{n/a}} || {{n/a}} || {{n/a}} || {{n/a}} || {{n/a}} || {{n/a}} || 3 || {{n/a}} || 1 || 4
|}

''Signal Ground'' is a [[Single-ended signaling|common return]] for the other connections; it appears on two pins in the Yost standard but is the same signal. The DB-25 connector includes a second ''Protective Ground'' on pin 1, which is intended to be connected by each device to its own frame ground or similar. Connecting Protective Ground to Signal Ground is a common practice but not recommended.

Note that EIA/TIA 561 combines DSR and RI,<ref>{{cite web| url = http://www.hardwarebook.info/RS-232D| title = Hardware Book RS-232D}}</ref><ref>{{cite web| url = http://www.t0rchthe.net/rj45console/index.html| title = RS-232D EIA/TIA-561 RJ45 Pinout}}</ref> and the Yost standard combines DSR and DCD.