I have a special label printer (GoDEX RT863i) connected to a Mac. It uses the CUPS system and is configured through a PPD file. Printing through the macOS print system generally works.
Now, I need to send some special commands to the printer via its xxPL (EZPL, GZPL, GEPL, GDPL) communication interface.
The manufacturer provides a framework for talking to the printer, but that's fairly buggy and thus not suitable (e.g. I cannot send arbitrary byte data because the framework uses NSString instead of NSData, making it impossible to send certain byte sequences).
So I want to talk to the printer directly. How would I accomplish that?
- Does CUPS provide a channel that lets me send commands to the printer?
- How would I go about talking to the printer's USB ports? Here's what
ioreg -r -c IOUSBHostDevice -lprints about it:
+-o RT863i@00442000 <class IOUSBHostDevice, id 0x100126a4c, registered, matched, active, busy 0 (3 ms), retain 20>
| {
| "sessionID" = 8582230593430921
| "USBSpeed" = 3
| "IOServiceLegacyMatchingRegistryID" = 4296174158
| "idProduct" = 1
| "IOReportLegendPublic" = Yes
| "IOPowerManagement" = {"PowerOverrideOn"=Yes,"CapabilityFlags"=32768,"MaxPowerState"=2,"DevicePowerState"=2,"ChildrenPowerState"=1,"DriverPowerState"=0,"CurrentPowerState"=2}
| "bcdDevice" = 1
| "bDeviceClass" = 0
| "USB Product Name" = "RT863i"
| "AppleUSBAlternateServiceRegistryID" = 4296174158
| "locationID" = 4464640
| "kUSBSerialNumberString" = "195003FF"
| "bDeviceSubClass" = 0
| "kUSBCurrentConfiguration" = 1
| "IOCFPlugInTypes" = {"9dc7b780-9ec0-11d4-a54f-000a27052861"="IOUSBFamily.kext/Contents/PlugIns/IOUSBLib.bundle"}
| "bDeviceProtocol" = 0
| "USBPortType" = 0
| "USB Vendor Name" = "GODEX INTERNATIONAL CO."
| "idVendor" = 6495
| "USB Serial Number" = "195003FF"
| "IOGeneralInterest" = "IOCommand is not serializable"
| "IOReportLegend" = ({"IOReportGroupName"="Power","IOReportChannels"=((5795982523037122560,12886081538)),"IOReportChannelInfo"={"IOReportChannelUnit"=72058100844068865},"IOReportSubGroupName"="State"},{"IOReportGroupName"="Power","IOReportChannels"=((5288471043487301632,4296146945,"Consensus Idle Policy")),"IOReportChannelInfo"=$
| "kUSBVendorString" = "GODEX INTERNATIONAL CO."
| "IOClassNameOverride" = "IOUSBDevice"
| }
|
+-o AppleUSBHostLegacyClient <class AppleUSBHostLegacyClient, id 0x100126a4f, !registered, !matched, active, busy 0, retain 9>
| {
| "kUSBHostDeviceForceSuspend" = No
| "IOPowerManagement" = {"DevicePowerState"=0,"CurrentPowerState"=1,"CapabilityFlags"=65536,"MaxPowerState"=2,"DriverPowerState"=1}
| }
|
+-o AppleUSBHostCompositeDevice <class AppleUSBHostCompositeDevice, id 0x100126a57, !registered, !matched, active, busy 0, retain 4>
| {
| "IOProbeScore" = 50000
| "CFBundleIdentifier" = "com.apple.driver.usb.AppleUSBHostCompositeDevice"
| "IOProviderClass" = "IOUSBHostDevice"
| "IOClass" = "AppleUSBHostCompositeDevice"
| "bDeviceSubClass" = 0
| "IOMatchCategory" = "IODefaultMatchCategory"
| "kUSBPreferredConfiguration" = 1
| "bDeviceClass" = 0
| }
|
+-o Printer@0 <class IOUSBHostInterface, id 0x100126a58, registered, matched, active, busy 0 (1 ms), retain 6>
{
"USBPortType" = 0
"IOCFPlugInTypes" = {"2d9786c6-9ef3-11d4-ad51-000a27052861"="IOUSBFamily.kext/Contents/PlugIns/IOUSBLib.bundle"}
"bcdDevice" = 1
"USBSpeed" = 3
"idProduct" = 1
"bConfigurationValue" = 1
"bInterfaceSubClass" = 1
"locationID" = 4464640
"IOGeneralInterest" = "IOCommand is not serializable"
"IOServiceLegacyMatchingRegistryID" = 4296174170
"IOClassNameOverride" = "IOUSBInterface"
"AppleUSBAlternateServiceRegistryID" = 4296174170
"idVendor" = 6495
"bInterfaceProtocol" = 2
"bAlternateSetting" = 0
"bInterfaceNumber" = 0
"bInterfaceClass" = 7
}
As you can see, it doesn't automatically install any serial port (to /dev/), so I think I need to use other means, unless it's easy to create an IOKit "driver" that matches the device and automatically installs a serial port (no idea if that's something that IOKit can do without any extra code)?