LaserJet 400 M401dn No Bi-Directional Communication

[KCCopyguy]

The box to check for Bi-Directional Communication is greyed out and not checked.  We use FM Audit and Agents on local installed printers for meter reading and toner supply alerts and require this feature.  All PC's are using the correct HP driver for this model, ver. unknown.  All agents do not report supply levels or meters.  

FMA tech support suggested using a Universal print driver, which we did.  We can now check the box for Bi-Directional Communication and receive meters, but still no supply levels.

[dansdaduk]

I don't have access to a LaserJet Pro 400 M401dn printer, nor do I have any knowledge of how FM Audit works. 

I have a printer from a similar model range: a LaserJet Pro 400 Colour MFP M475dn printer; the printer driver I use (on a Windows 10 Pro 64-bit system) is identified (in the About tab of the Printer properties dialogue) as:

"HP LJ300-400 color MFP M375-M475 PCL6 (61.120.4.12262)"

"UPD version: 5.3.0.12262" 

In the same dialogue, on the Ports tab, the "Enable bidirectional support" checkbox is unchecked and greyed-out (so I can't select it); the port used is the "HP Standard TCP/IP Port".

I can view toner levels via the Embedded Web Server on the device (i.e. I point a browser at the IP-address of the device).

I think (can't remember for sure) that when indivudual toners reach Low or Very-Low levels for the first time, a pop-up alert is shown (presumably courtesy of some HP add-on).

I can also see the toner levels (maximum and current) in a rather more cryptic view, using one of the free ''snmpwalk' applications (which basically reports all available SNMP items available); for example:

SNMPv2-SMI::mib-2.43.11.1.1.8.1.1 = INTEGER: 100
SNMPv2-SMI::mib-2.43.11.1.1.8.1.2 = INTEGER: 100
SNMPv2-SMI::mib-2.43.11.1.1.8.1.3 = INTEGER: 100
SNMPv2-SMI::mib-2.43.11.1.1.8.1.4 = INTEGER: 100
SNMPv2-SMI::mib-2.43.11.1.1.9.1.1 = INTEGER: 7
SNMPv2-SMI::mib-2.43.11.1.1.9.1.2 = INTEGER: 75
SNMPv2-SMI::mib-2.43.11.1.1.9.1.3 = INTEGER: 74
SNMPv2-SMI::mib-2.43.11.1.1.9.1.4 = INTEGER: 75

where:

• mib-2 is (I think) the standard 1.3.6.1.2.1 prefix.
• The 8.1.n values show the maximum levels of the Black, Cyan, Magenta, Yellow cartidges.
• The 9.1.n values show the current levels.

I've no idea how FM Audit attempts to obtain supply levels and meters from your printer; I don't know if it uses SNMP (which would imply using a network connection), or some other type of 'status-readback' mechanism.

... and similarly, I don't know if this has anything to do with "bi-directional  communication".

[dansdaduk]

I'm not all that familiar with decoding the Object Identifiers used with MIBs, so the example I posted for my LJ M475dn may not be applicable to your device (although it probably should be, since (I understand) there is a common 'core' set of OIDs used by printers).

A MIB for the LJ 401 model is  attached (within a .zip file); the prtMarkerSuppliesLevel item is defined therein as:

prtMarkerSuppliesLevel OBJECT-TYPE
    SYNTAX      INTEGER
    ACCESS      read-only
    STATUS      optional
       DESCRIPTION "The current level if this supply is a container; the
        remaining space if this supply is a receptacle. If this
        supply container/receptacle can reliably sense this
        value, the value is reported by the printer and is
        read-only; otherwise, the value may be written (by a
        Remote Control Panel or a Management Application). The
        value (-1) means other and specifically indicates that
        the sub-unit places no restrictions on this parameter.
        The value (-2) means unknown.  A value of (-3) means that the
        printer knows that there is some supply/remaining space,
        respectively.
                Additional information:
                Print Cartridges measure life based on the three
                components: toner, developer and drum.  These Print
                Cartridge object (1) report the lowest of these
                three factors in units of tenths of grams.  Print
                Cartridges that are not installed will return a value
                of 100."
::= { prtMarkerSuppliesEntry 9 }

[dansdaduk]

Perhaps your reference to 'bidirectional communication' is something to do with the use of snmp 'traps' (a subject about which I know very little) to generate unsolicited messages (rather than the on-demand reading of OIDs by snmpwalk or similar tools)?

If it helps at all, returning to my LaserJet M475dn printer: the Embedded Web Server shows (on the Networking tab):

 

and on the workstation, the relevant Printer properties dialogue: 

[KCCopyguy]

The local installed printers are USB.

[dansdaduk]

snmp is Simple Network Management Protocol, so I (as a relative novice when it comes to communications issues) would expect it to be used over a network.

However, this FM Audit help page indicates that they can use the protocol over a USB connection:

I can only speculate as to how snmp 'get' actions might work via a USB port, and what it would depend on (perhaps it uses Peripheral Management Language 'get' commands, which may themselves be embedded within Printer Job Language commands?).

[dansdaduk]

... and this Device support help page may also be relevant:

I don't know what 'Cov. Sum' and 'Cov. Sq. Sum' represent.

[dansdaduk]

This WebJetAdmin document ("Discovering PC-connected devices") may provide some background information about SNMP proxy agents, which (if you can wade through it all - it's quite technical in places) might give you some clues.

... and what driver you are currently using may possibly be relevant; the above document states:

So perhaps you are not using a UPD driver, or a suitable DOT4 driver for the USB connected device(s)?

[dansdaduk]

... and that document also includes the following information:

[KCCopyguy]

Thank you, this last chart was very helpful.  Makes me wonder why FMA tech support hasn't mentioned any of this.  One question.  How do I know if my printer supports PJL or PML?