Com­pa­ring phy­si­cal lay­er CAN dia­gnostic devices

You have pro­blems with your bus, in your sys­tem or at your customer’s site. You have to mea­su­re and stop gues­sing – what you need at this point is a dia­gnostic device.

The mar­ket is con­fu­sing, they try to decei­ve with fal­se pro­mi­ses but giving no real com­pa­ri­son. We try it and com­pa­re the GEMAC devices. For this com­pa­ri­son, we take the three devices that do mea­su­re at the phy­si­cal lay­er. CANalarm has spe­cial fea­tures, which has not­hing to do with phy­sics and CAN­vi­si­on is as pro­to­col moni­tor working on logi­cal lay­er only. The­re­fo­re the­se two pro­ducts are not lis­ted in this com­pa­ri­son.

A table like this with fea­tures can only be some kind of hint. Fea­tures dif­fer from device to device, even when both of them have it. The­re may be a dif­fe­rent under­stan­ding of a fea­ture or a dif­fe­rent expec­ta­ti­on. Plea­se open a ticket wit­hin the sup­port area if the­re are spe­cial ques­ti­ons run­ning in your mind.

In this arti­cle, we go even deeper into the ago­ny of choice and make recom­men­da­ti­ons.

revi­sed and updated March 2017



In Gene­ral

Bus sys­tems (CAN, CANopen, Device­Net, SAE J1939)
Auto­ma­tic baud rate scan /​Node or Iden­ti­fier Scan● / ●● / ●● / ●
Export data
Print func­tionScreen­shot or Export
Mana­ge mea­su­re­ments

Online Moni­to­ring

Dis­play bus sta­tus
Dis­play bus traf­fic load● with pro­gress
Dis­play error­frame coun­ter (abso­lu­te /​per second)● with pro­gress
Dis­play optio­nal CAN sup­ply vol­ta­ge● with pro­gress
Dis­play shield vol­ta­ge● with pro­gress

Abso­lu­te mea­su­re­ments CAN_​H /​CAN_​L against V-

Com­mon mode vol­ta­ge
CAN Level abso­lu­te /​dif­fe­ren­ti­al● / ●

Bus wiring

Cable length
Ter­mi­na­ti­on resis­tors
Loop resis­tance (bus, power sup­ply)

Node Mea­su­re­ment

Bus sys­tem CAN with ID scan
Bus sys­tem CANopen with Node­ID-Scan
Bus sys­tem Device­Net with MacID-Scan
Bus­sys­tem SAE J1939 with Source­adress-Scan
Qua­li­ty level mea­su­re­ment of all nodes
Qua­li­ty level, dis­tur­ban­ce-free vol­ta­ge ran­ge, edge steep­ness
Dis­play oscil­lo­gram, dif­fe­ren­ti­al signal, phy­si­cal or logi­cal deco­ded
Dis­play oscil­lo­gram, abso­lu­te signal (CAN_​H /​CAN_​L vs. refe­rence ground)

Pro­to­col Moni­tor

Send CAN messages
Recei­ve CAN messages
Sym­bo­lic decode CAN messages
Trig­ger /​Such­funk­tio­nen
Trace CAN messages (con­fi­gura­ble start- /​stop con­di­ti­ons)
Recei­ve /​decode CANopen messages
Recei­ve /​decode SAE J1939 messages as well as ISOBUS and NMEA 2000

Online Trig­ger

Record­ing timemax. 1 weekunli­mi­tedmax. 10 years
Gau­ges 4x phy­si­cal + 4x logi­cal
E‑Mail warning
Con­trol point access (SNMP)
Access with brow­ser (HTML5, mobi­le devices)
Error out­put
Dis­plays oscil­lo­gram on sin­gle mea­su­re­ment
Tone signal on trig­ger


Func­tion unsup­por­ted
in basic ver­si­on inclu­ded
can be unlo­cked by licen­se
inclu­ded in licen­se